Hmmm...interesting thread. Where do I start?
MAGNAchrom, I feel your pain. Take it a bit as flattery, but still, I wouldn't want anyone impersonating me. No matter what. Craig List is such an unmoderated sinkhole of crap.
snergon, I also feel your pain. I was a bit taken aback about your comment regarding the agency. I personally prefer agency model over internet models. In fact 90% of the models I shoot are agency tests, or the model just likes to shoot with me, so she calls me up.
Now I have shot models in Toronto, Montreal, London, Prague, Chicago, New York, Philadelphia, San Diego and Los Angeles and most of them were agency models because they are reliable. Even though I have a network of internet models, I find with them, you have to get references before you can book them and have confidence they show. I always get references from fellow photographers in the city I am shooting wrt internet models. It would be a huge waste of time and energy for me, my MUA and often a stylist and assistant if I got a no show.
Another good source of models is fellow photographers. I would often get model references from them and I haven't been burned yet from that route or the agency route. I have once via the internet route but I also book 2-3 models so a no show is no issue for me. And if all 3 show up one's in make up, one's in hair/styling and one's with me on the set.