Guild Wars 2

Can Anet see the number of +1 on posts?
Or more importantly, if they can, are they using that data?

They have said before that they use that to pick out popular topics

I’m sure they can; they have access to the backend. The forum, itself, indicates (and shows us) if a thread has an abundance of +1s.

Probably, but I rarely use this +1 feature since it is boring to me if we cannot see exact data ourself. Downvoting would be another thing to make it more used by me.