Summer camps (and the winter camps held over Spring Festival season) CAN be legal, but many are not fully legal...

My biggest problem with them is that virtually none of them offer a legal visa or residence permit to the teachers who come in to teach them. It cuts into profits to offer you a legal visa; most will tell you that it's OK for you to come work on a tourist or business visa. It's done a lot, but it's not necessarily OK...working for a Chinese company here without a Z visa/residence permit is plain old illegal. Period. Teachers can be and are fined, deported, and worse for this.

Also, the hours of camps tend to suck...very long days with very few days off. When you aren't working, you're too tired to do much.

There have also been a lot of problems with food, housing, abuse of free time (ie surprise demo classes, etc.) and so on in connection with camps.

Schools LOVE camps because they are extremely profitable for them. However, while there may be some good ones, many of them tend to be a pretty bad deal for the teacher if you look closely at what you have to do and how you have to live.

Personally I NEVER work a camp and can't recommend them to anyone.