Have you gone to a bank teller window recently for a cash withdrawal or deposit recently?  All the banks around here have a "bill flipping machine" that riffles through the stack they're handling.  Most tellers put the stack through twice, turning in over between runs.  Those little machines could be recording serial numbers -- I know the technology that could do it.  
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So you withdraw some cash (teller or ATM), and the bank associates those bills with your name.  Then a hooker deposits some of those bills at that bank. or a different one, and the bank associates the bills with her name.  A database join, and your name and hers are connected.  
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It's still being said that cash is anonymous.  
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Is it still true??

...to make sure there's no human error.  I deposit and withdraw large amounts of cash I've never seen them put the bills in twice or turn the bills over.

Tracing would imply each and every transaction is recorded. With cash, that's impossible because you'd scan the serials only at banks.  

Yes, Yes it is.

The end points are insufficient to prove the intermediate.  You take out five bills.  Later some lady deposits those five bills.  Later still she is arrested for soliciting.  They examine her bank records and correlate your transfer.  What does it prove? Speculation is not admissible as evidence.

So I draw some cash out of the bank, I spend it on a hooker, she in turn buys some pot with the money, the pot dealer now jumps on a plan with that same cash in hand and goes to Vegas where he loses it, The casino deposits those bills and the serial numbers trace back to my cash withdrawal in Dallas. As far as anyone can prove GaGambler is back at the tables again. lol

I still get the occasional "old" style 100s from the bank, AFTER they have recorded all of the serial numbers using the counting machine. Sometimes, I ask the teller if I can trade the "old" 100 for a "new" 100 which they then do MANUALLY! Without recording the serial numbers!  
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If some chump gets the "old" 100 in a simple transaction (w/o a rescan), that's their problem. ... Hay, wait a sec ... that's MY problem if the chump uses the "old" bill, still linked to me, for something criminal!  
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Maybe I should play it safe and rob a bank instead making legit withdrawals.

-- Modified on 7/26/2020 6:41:35 AM

of you shit, but I can't find anything incorrect about BigPapsmear's response.  He got one right.  

Please back up that flat assertion, and say how you know that the machines are simply counting the bills.  
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I mean it.  I would feel a lot better if I knew that.  I hope you can convince me.

No.

You're answering a question I did not ask, with the obvious answer that I had of course already figured out.
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And you're accusing me of drug use, which is wrong and sounds like simply trying to distract from the question.

If cash is scanned at banks, only banks, you're entirely correct that full forensic tracing is impossible.  I trust that was obvious to all of us.  
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The question was not about full tracing, but about a failure of anonymity.  If you accept that banks are, or even could, scan cash serial numbers, then what are the implications for the anonymity of cash?

riffed, not scanned, which means they are overlapping.  You can't scan them I like that.  The same machines are used by businesses that take cash and casinos.  Its just a fast way to count.  Nothing nefarious going on at all.  Its like when you hold one end of a deck of cards and riff at the cards on the other end.  The faces of the cards are partially  covered by the adjacent cards.  You can order one of these online if you want to examine for yourself how they work.  There it no way to turn it into a scanner.  Feel better?

I'm not that paranoid, yet.  Your second paragraph is entirely obvious.  
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Have you  examined the workings of a bank bill-counter, to know that the bills stay overlapping through the entire path?  If so, thanks and that is reassuring.  For now.

To be on the safe side, alter the serial numbers on your large bills (those used for specific purposes only).  With a single stroke from a ball point pen, 1 becomes 7. Close the loops to change 3 to 8. Change an F to an E or a P to a B. Woila! (Note how I changed the V to a W with two short pen strokes.)

Sorry, I'm still not following. Is this about some larger point of anonymity being breached?

With your permission Valida,

The counterfeit detectors and businesses are not likely to accept the bills that have been altered.

Your actual question is too stupid to answer.

Numbers like that used to be scary-expensive.  We're both old enough to remember back that far, sure.  

[Copied from linked page]

You seem to be thinking of cheap portable counters like these that riff but do not scan.  Those are not what one sees at teller windows in banks.

It's not even a secret -- you can buy 'em in Walmart, now that I go look.  The technical capability was obvious.  The contingent fact of its commercial availability  is also established.  

Actually it's only about the small point of anonymity lost:  
Every bill you withdraw or deposit in a bank is (potentially) associated with your name, account number, date, and time.  
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That is not anonymity.  
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Larger questions of how pervasive those records are, and who could do what with those records, require discussions that this forum is clearly not sufficient for, in light of the quality of responses to the small question.

You say that bill counters are examining the serial numbers in sufficient detail to trigger such alterations.  Is that consistent with "only riffing"?

Not to mention that doing so is a federal felony for altering a bank note.

I think one might want to dig a little deeper than that. Yes, you can get counter machines that will record the serial number, and even print them out. But I didn't see anything about how to enter other information, like the transaction details for the customer that was making the cash withdrawal.  That certainly could exist but then you are also getting into recording and transmitting all that AND then matching to the return deposit to find out where those bills came back into the banking system.  

we need to toss entire US government in jail as the $ are always connected with nearly every crime. We would not have legal tender laws without Congress, the Treasury is part of the Executive office, and the SC has never over turned these laws. We could probably get them on trafficking charges too.

It would be just so much easier to put some semiconductors in the bills and some antenna. We could have any number or readers -- your phone's emergency functions, automatic doors, your car.... Phones would probably be best as they might actually be able to capture 90% or all cash exchanges.

Should have gone with the chain of events that get each of the 5 bills deposited in a bank in a different city, in a different state, on the same day. Then the feds bust you for breaking the laws of physics

That's the difference between a $150 bill counter and the $2200 CR1500. But it still doesn't link the serial numbers to a particular transaction / customer. That isn't in the software.  
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The US Post Office uses high speed scanners to read codes and stamps.  Postage stamp scanning isn't optical in the visible (looking at a picture, trying to figure out whether it is upside down or sideways, trying to find the number (55 cents) or letter (Forever stamps)). The stamps also have a UV or other non-visible overprinting that can be used to verify the stamp, verify the denomination of the stamp, and allow the machines to flip the envelopes so the postmark ends up on the stamp itself.  
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Which leads me to wonder ... When will they start adding a machine readable invisible barcode or number code on our beloved Benjamins? Then, the price of that $2200 machine might come down and they'll add the tracking software, too.

Would be when the overlords determine to do away with cash due to some arbitrary reason, such as a pandemic spread....that would make things uncomfortable around here, among other places, wouldn't it?

there are electromagnetic features on bills, specifically put there to make scanning easier.  The fancy bill counters use them too.

I'm talking about businesses that use a counterfeit detector where they put a bill in one at a time at the check out terminal, and it detects whether its legit or counterfeit by flashing a green or red light IN ABOUT FIVE SECONDS.  Not sure what the technology is, but its not the same process as riffing though a stack of hundreds in the same five seconds just to count them.  I was responding to Imp on the subject of altering US currency.  Adding writing to a bill may trigger these detection machines.  

His advice should NEVER be taken literally, and even on the rare occasions that he gets something correct,  he always  looks to find the most complex answer to the simplest of questions.

They would have trouble proving who modified the bill, unless the idiot admits it (a large number of convicted people are only convicted because they admitted guilt.)

It wasn't an issue of WHO altered it, it was an issue of trying to pass the bill at a retail establishment that uses one of the electronic counterfeit detectors.  Clerks are simply told if they get a red light on the scan, don't take it.  They are not likely to examine it further to determine the extent of the alteration.  The machine eliminates the possibility of human error in deciding if a bill is legitimate, and that's why more and more retail places are using them.

That is really silly. Do you think the cops have a case against you because a girl deposited cash you once had in your hands? Maybe the single best piece of paranoia ever. Just quit already!  

Seriously, the Chinese are trying to hack our computer systems a few thousand times each day.  The North Koreans have been counterfeiting US currency for years.  The Russians are stealing everything that isn't nailed down. Non-state players are working every day to disrupt banking and commerce.  But someone here really thinks the FBI, the Secret Service and a host of other agencies have nothing better to do than to track down the currency I gave to a provider last week?  Even in support of anti-human trafficking efforts, I have to believe this would be a tremendous waste of time, resources and energy.  If you really think our combined law enforcement has the time and capability to follow countless cash transactions each day, may I recommend to you some Jason Bourne novels.

I think it's a huge assumption that she will deposit your payment rather than spend it. Anyway, even if she is like a pizza shop and deposits all her payments received at the end of the day, the cash could have gone through many hands between your ATM withdrawal and the provider's deposit. Anyway, your bank isn't in the business of tracking the use of each bill.