Well, are they really? You often spot a sign like this one at an animal rights demonstration, saying that animals are people too. Of course this statement makes no sense, but they’re trying to make a point that animals have feelings and shouldn’t be treated as violently as they are. Also, this photo wasn’t taken at a demonstration for animal rights, but at the Rally to Restore Sanity and/or Fear, so it makes no sense whatsoever.
However, a “Bears are people too” sign is one I’ve never seen before. And the addition of the bear mask really drives the point home (though it looks like a lion). What is he protesting? Wearing the bear mask may attract attention, but I can’t imagine it helps him to gain more sympathy.