I don't know for sure, but there's been quite a bit of controversy about them in the last year, mainly because of their whitelisting (https://en.wikipedia.org/wiki/Adblock_Plus#Controversy_over_...). I switched to ublock origin, works well for me, others recommend ublock (there's been quite a bit of drama between the original dev who's responsible for ublock origin, and the new dev who's responsible for ublock, I can't really recommend one over the other, if you're interested you might want to do some research there)