BuddyPress.org

Good Afternoon Ladies and Gentleman,

I have two questions. How do I add a captcha to my user registration page to prevent bots from spamming my website?
I currently have the following Plugins installed: Buddypress, Facebook Link.

Conceivably, I also would like to do is this:
When someone creates an account, they link it to their facebook. Thereafter, the account details from their facebook is added to current profile
Its pretty much the same idea as what Tinder does when registering and using
http://www.gotinder.com/

Not sure if a plugin exist, if one does, that kicks ass. If not, does anyone know where i can find a good tutorial explaining, step by step, how to do this.

Thanks,
GalenL