Is this about the Collins project or the reorderability/satisfiability posts?
If they merely annoy you for personal reasons (style, tone, topic, etc), tough. It's a free country and there is relative free speech on Yahoo Answers. People do have a right to hold and express annoying opinions and you don't have a right to be free from that annoyance. All you can really do is block the user (you can still see what they post, I think, but it will prevent them for clicking into your questions to answer and annoy you) or just ignore them by not clicking on their questions or reading their comments.
This is what's known as personal responsibility. It is rare to find it anymore these days, but it does still exist.
If the answers are actually offensive, and Yahoo provides a community guidelines list of what constitutes actual offensiveness for the community, then you should report them. False reports based on personal annoyance count against you though, so make sure they are actually breaking the rules of the site before reporting them.
Who is it? Is it me? Because I know I've ruffled a few feathers. Oh my god, it's me isn't it?