More than a coincidence.  

Recently I have needed WIFI access while on the road and pulled into a hotel parking lot to get online.  I have done this numerous times in the past and never had a problem.  

There must be a new trend in LE technique across a few Minneapolis suburbs as I have experienced this phenomenon 3 – 4 times before I altered my pattern. I was sitting in my car surfing for a short period of time and a LE car pulls into the lot, does a slow cruise and either stops near my car as if he was going to get out and talk with me or gives me the stink eye.  They are really aggressive in this practice and I have even seen them work in groups targeting a hotel.  The first time this happened the cruiser pulled right in front of my car and blocked it.  I kept my head and put my computer in the bag, left the car and walked into the hotel figuring that gave me a lot more options than staying in the car.  When I left the hotel ten minutes later he was gone.  I doubt they received a call on my activity as I was discrete, but were just out fishing. The weird thing is I was always dressed as a business man, clean cut and they wouldn’t find anything if they ran my plate.
Ironically every time this happened I was not engaged in the hobby, but surfing in a legitimate fashion so they are really out to hassle the law abiding citizen and who ever else they happen to dig up.  

I know enough to keep my mouth shut in these situations as they really don’t have anything, and if you start talking they can start building a case out of thin air.  

If you are in hobby mode I would strongly suggest not hanging out in hotel lots as you may end up getting a lot more attention than you are looking for.

I'd never though about whether it's illegal, but it is.

Federal law: the Computer Fraud and Abuse Act. Paragraph (a)(2) maintains that anyone who "intentionally accesses a computer without authorization or exceeds authorized access" has committed a crime ... [then it's up to the states and some are more strict than others]

I didn't find the Minnesota info in my quick search.

Great post but how can you achieve unaithorized acess on an unprotected system.I also believe that this is more a case of regular patrol of the lots for criminal activity and not related to computer.If your hacking in different story

Using an unsecured network = bad idea.
To me its worth it to get a tethering application and use your mobile device .
rather than having my activity possibly watched by another while im mooching off their free wiFi.

Are you saying that this applies to the OPs use of Wifi?  Two problems with that; first, wifi is not a "computer."  Also, that quote is taken out of context.  One must obtain certain information through the unauthorized use of a computer to break the law you cite (I pasted (a)(2) below).

(a)Whoever—
(2) intentionally accesses a computer without authorization or exceeds authorized access, and thereby obtains—
(A) information contained in a financial record of a financial institution, or of a card issuer as defined in section 1602 (n)  [1] of title 15, or contained in a file of a consumer reporting agency on a consumer, as such terms are defined in the Fair Credit Reporting Act (15 U.S.C. 1681 et seq.);
(B) information from any department or agency of the United States; or
(C) information from any protected computer;

END OF MESSAGE

My thoughts exactly.  I don't even bother with tethering though, I just use my phone on its own.

I think it is less about the WIFI than they will be in your face if they see you sitting in your car and not exiting to get luggage or leaving the car to go into the hotel.  Sitting in the car for any length of time is asking for very unwelcome attention.

First, I agree with most posters that it's about the hanging out in the parking lot, not the WIFI use. My preference is to make that last call from somewhere nearby, NOT the parking lot.

As for Minnesota, it looks like Minnesota Statute 609.89, subdivision 1, paragraph (a) is probably applicable even for simply WIFI use. Computer theft includes:

(a) intentionally and without authorization or claim of right accesses or causes to be accessed any computer, computer system, computer network or any part thereof for the purpose of obtaining services or property; or ...

The "obtaining services" portion would come into play. Before my home system was password protected, etc., my service was slowed down by intruders (meaning they had stolen my ability to use my own service).

I've never heard on anyone getting into trouble just using someone's WIFI, only for using it to access files on someone's computer.

https://www.revisor.mn.gov/statutes/?id=609.89

True but a hotel, which has to potentially supplies services to an entire hotel full of guests, isn't going to see an impact if a couple of people are accessing an unsecured network from the parking lot.  I suspect LE would only be interested in something like that if they thought they could leverage it into something bigger.

I think you might try going to MacDonalds or other fast food parking lot that provides WIFI to surf, will probably draw less attention and they provide for their customers, so go in and buy something and there's no problem.

Find a coffee shop and plop down with a laptop and you'll fit right in.  Park near the place and you'll probably get the WiFi and you'll have a whole lot less issues with LE. Hotels are hot spots for all sorts of activities that the LE dislikes. As a business traveler, stuff that looks normal at the hotel at 7 PM looks odd at 2 PM. Most businessmen are gone during the day so the people there are suspect.

I use a mobile access device, so WiFi isn't an issue for me.  I still avoid sitting in parking lots.

Only saying because phones can be a bit fussy with certain websites, Not everyone's device is flash enabled and mobile versions often lack features. That's why.