2FA via text message could also help to reduce the number of alt accounts and hence reduce the amount of scams. Registering based on unique email address and IP can easily be manipulated, but requiring a unique mobile/cell number makes it more difficult to create multiple accounts. Sure scammers could buy a whole lot of $2 prepaid sims, but it makes it more costly to maintain these accounts. Also people might be less inclined to sell their account if it is tied to their mobile/cell number.
2FA via SMS might be problematic when the forum user base is spread over dozens of different countries. I remember it took me 2 hours before I got a msg with a code on my European SIM card to access my gmail account when I was in India and I heard in some countries it's worse.
GA works well on bitcoin and non-bitcoin websites, Theymos knows people are interested in it and I hope he will decide to implement it.
