This looks very typical of what peoples you own money to could do. I never understood the logic. They would be better just taking the stuff instead to at least pay some of the debt but i supose they think its some form of payback since you didn't paid? Anyway. Could be that.
But the graffiti tend to show more of a jealous ex boyfriend or such. I don't think collectors would tag slurs on the wall.
Now i hope this person is ok and can turn her life around.
This is not the first time i will say this but yes the darkside of the business exist. I try to stay away as much as possible from it but sometimes you just can't know. You say that SP was very popular, charging a lot, i assume she was known as a high end indy merb advertiser, so someone i could had very well met and never suspected to be into this... That said, there is a bad side in just about everything. I am personally at peace of mind with myself and what i do. I pay money for a service that is consensual between 2 adults. If that person was not a young attractive women, and a guy instead, maybe they would resort to crime to pay their drug, or just end up on the street. Did the work itself lead to this? Possible. But there is numerous stories of celebrity falling into drugs and issues because they had the money for it at the time.
My point is, if its really working as an escort that "mentality broke her", its sad and i wish she could had just leave the job before it got to this point, but its not a certainity at all, maybe she just liked partying and drugs and thats what caused her decline.