Blizzhackers

How would you go about developing a Facebook friend add bot in either java or c++?

I'd use a framework intended for automating website testing, like Selenium. Then I would use Python or Ruby or Haskell or something else more laconic than Java and more safe than C++.

First, though, I'd explore what public APIs Facebook exports. For mobile apps and whatnot - it may be possible to avoid doing any RE, and just use the stuff they give you. (Still wouldn't use C++ for this, you don't need memory or CPU performance since your bottleneck is the network + remote service rate limits.)

http://developers.facebook.com/

^^find your APIs there.