I'm not a heavy user of gdb but every now and then I have to pull it out and use the basic features that I learned in a tutorial one day. I can't believe I have never heard of reverse debugging, would have saved a ton of time.
This article is kind of only half-thought through. Facebook is making contact to the user on behalf of this person that claims to be 'advancetehri', it is not a 'cold' invite by Facebook. This user 'advancetehri' used the invite a user feature and put this person's number in.
Evil plan to grab new users? No.
I feel like a vast majority of people take every single chance they get to argue that Facebook is out to get them.