There are many ways to use photo rip offs, starting from
Real-Mary, Real-Mary-Ad, Real-Mary-Pics, Real-Mary-Phone, Real-Mary-Everything
1. A stolen pic can be used to siphon customers who think they are contacting the real Mary.
Susie uses Mary's REAL Pics in an ad for "Mary" but uses Susie's Phone and Contact info. Susie is pretending to be Mary to take advantage of Mary's reviews or good reputation.
On TER, guys report, "Watch out for Mary! She's a con artist using more than one phone and claims to be on Long Island and Manhattan at the same time." That hurts Mary's business and rep and it is not her fault.
2. A stolen pic can be used to create a completely new person.
Susie uses Mary's REAL pics in an ad for Susie with Susie's Phone and Contact info.
On TER, guys report, "Watch out for Mary! She uses multiple names and phone numbers and accounts! Must be a rip-off artist!" Once again, the picture thief has damaged Mary's business and reputation.
3. A stolen pic can be used on other sites, such as modeling sites, such European sites.
"Warning! Mary claims to be a Provider in NYC but I just found her pics on a modeling site in the UK. Mary must have stolen the models' pics!" Well, it's actually the other way around, but too late to undo the damage done to Mary's business.
4. A stolen pic can be used by the robot-driven sites to increase the number of their ads (and, they hope, increase revenue as Kerri pointed out) but that can also lead to undesired calls, contacts and distractions to someone like Mary who wants to be in control of her ads and where they post.
5. Have stolen pics ever ended up on non-filtered sites, such as Facebook or Pinterest? I don't know. But if Mary was assuming that the normal search engines (that have default filters for certain adult sites) wouldn't find her pics, they are now showing up in the main search engine hit lists. Now other parts of Mary's life is screwed up, not just her business life.
I'm sure there are other scenarios but I don't have the time to write them up. It may seem OK not to worry about your pics being stolen at first, but it could end up having a major negative impact.
All I know is, I don't mind the waterkmarks. They serve a useful purpose and authenticate the picture, especially is the watermark is a web address or phone number. (Unless it's a non-watermarked stolen pic with a new watermark added by the picture thief!