After revisiting and pondering various wank and drama (fandom and political), I've come to a conclusion as to what is the most maliciously misused punctuation out there: the quotation mark.
When representing spoken language, as in a fictional story, it's fine and dandy, but a problem I've noticed arises when it's meant to represent quoted language. For example, let's assume Amy -- a person I just made up -- writes about her bad experiences with cats. Her roommate kept a filthy litterbox, the cat had fleas, got pregnant and peed everywhere. Consequently, wanted to get rid of it and "hates that cat". Later, when talking to friends, I relate that Amy said "I hate cats." Without any additional information, such as mentioning I'm paraphrasing, people may believe Amy is a cat-hater.
Mine is a simple, benign example, but my point is this is a something I've seen people do, sometimes intentionally. In my opinion, it's misleading and, when it comes to certain issues, potentially harmful. In my example, "I hate that cat," could be conveyed to a third party as, "I want to hurt that cat," and now Amy is not only a cat-hater but an animal abuser as well.
I think the internet, however, has made it harder to misquote. It's easier to go back and point to the record of what was said. Unfortunately, in a way the damage is already done. The belief of what Amy supposedly said is already in people's heads, and some folk stubbornly prefer to believe what they thought she said rather than what she actually said, even if in black and white. Look at the contradictory statements of politicians highlighted by programs like The Daily Show. Even when presented with proof, they deny. Annoying, isn't it?