Wait, are you talking about memes submitted in PoliticsTOO?
PolticsTOO is a private stream. Mods of private streams do not have to operate with the same fairness as IMGFlip mods. If an IMGFlip mod is harassing you, that is a serious allegation. If a mod of a private stream refuses to feature your memes, that's a private matter.
I've never seen an IMGFlip mod... I don't think they're as obviously indicated as private stream mods are.
I'm typically not a fan of censorship either. This is why I rarely post to private streams like PoliticsTOO. I do make commentary but if they chose to remove my comments; I assume that they would be killing their own viewer count that help keep that private stream alive.
In fact, though I cannot find which meme it was, recently, a slew of frequent PoliticsTOO posters were admonishing the mod there for deleting comments and possibly memes despite the fact that that went against their own stated policies. The Mod's justification being that if they had posted something like that in Politics "it would've been downvoted to oblivion," I'm paraphrasing as I'm going off of memory. Which, I admit, is not the best thing to go on.