For the most part these fake photos are guilty only of bait and switch. The fraud and identity theft usually comes from ads with pornstar type photos but no phone number. You send them a note and they reply with some bullshit story about needing to screen you for age and to ensure you are not an officer of the law. They advise you to go to a website, enter your cc info and you'll be directed to their site with direct contact info.
If any one is actually dumb enough to follow through with a such a transaction they deserve to take the hit. Sorry but it's one thing to be robbed without being aware of it, but giving your cc info like that is like handing them your car keys or wallet.
The scam is more successfull in the USA where prostitution is illegal, the "screening" process gives a sense of ligitimacy to the whole operation, thus duping the unsuspecting client. In the states it seems both providers and clients are paranoid about being busted, this scam plays off that fear.
The cc scams don't seem as frequent here as they were a while back. I used to bait them along and then tell them to fuck off, I got some colourfull replies back, lol telling me that they were the police and I would be contacted or giving me shit for wasting their time, too funny. Cons don't like being conned!