Aside from the various legal issues, there are two other consdierations:
1. Flapnecks have a deserved reputation for not adapting well to captivity - stories of people keeping them as kids are normally semi wild ones that were returned to the wild after a few months.
2. Any wild chameleon that is added to collection is very likely to be carrying parasites, which it will pass on. It is likely that, unless you utilise a knowledgeable vet, you will not treat your wild chameleon sufficiently with the few things that you can easily buy. There are some parasites (blood, guts, etc) that will require repeated careful attention and specific treatments. You may think that your chameleon is THE one that is parasite free - it won't be. However, it may have a natural immunity that will hide the problems. Captive bred chameleons will not have that same ability and you could lose your collection within days.
Is it really worth the risk?
David
http://www.sa-chameleons.comhttp://www.mantispress.co.za