I don't know if I'd consider this user a troll, but a user named macrow has been downvoting any suggestions with Emma Watson, Anna Kendrick, and Amanda Seyfried for no apparent reason. By the way she seems like a child based on her comments on certain stories and her casting suggestions on certain stories. If you don't want her to do this, then I recommend you block her.
She only voted anything for that particular actor and what makes me confused is that she upvotes like only one role for that actor and downvotes the rest of it.