They don't post things I don't like -- they merely like things I don't like and the things they like post things on their behalf and without their knowledge.
Even if you put a person on "ignore" the ads will still show up.
From talking to other people about it (and also from the only one other comment in this thread that goes "right on, I thought I was going crazy") I'm thinking it might be a limited rollout so far... a lot of people seem to have no idea what I'm talking about, but how could you miss it when your newsfeed suddenly starts acquiring a bunch of stories posted by random jerks you've never heard of?
Even if you put a person on "ignore" the ads will still show up.