I blocked him ages ago. Best decision I made on the forums.
Social media and third party polls have already had problems with bot spam, sockpuppetting and social engineering campaigns aimed at influencing discussion a certain way or artificially inflating certain points of view. Stuff like this has gone on for even longer than some people may think. If you're familiar with comics, people were really mixed on Jason Todd, which led to a phone vote on whether he lived or died. Someone rigged the vote so that he'd die. The results weren't an accurate reflection of comic fans' opinion on the matter.
Jagex has mentioned having their servers targeted by multiple cyberattacks and RS has a history of botters harming the game. Those are exactly the kinds of people who do stuff like rig feedback and they already have motive to do so to Jagex specifically. We're at serious risk of the botters/hackers taking over the game or at least seriously damaging the quality and accuracy of the feedback Jagex will be recieving on the game and community.
How to block a forum user