And by that, I don't mean porn writers who steal actual characters and shit out loads of insane fuckery (also, this in fact can be prosecuted if characters are trademarked, which they usually are), but people who apply the names to themselves.
Aiken Drum is obviously Julian May's king of all that is awesome. But originally, he's an unemployed elf (from Scotland, or from the Moon) who will do household work in exchange for food.
So I can jolly well name my character Aiken Drum and do whatever I like short of rewriting the stupid parts of the (otherwise well-written) books and republishing the whole thing. Because names and plot ideas cannot be copyrighted.
Names can be trademarked. These form the foundations of character portfolios and character-based enterprises. Note that the spirit of the law does not strive to protect the copyright holder (although the letter does). Instead, it is intended to protect the buyer from wasting their money on a mispresented object. So your character has to be significant enough to begin with and you have to be able to persuade the jury that an overwhelming majority of customers will be looking for your product and not the would-be counterfeiter's. The success of this endeavour depends on whether the name is a previously used (human) name or a whole-cloth creation and whether it is used in the title of the potentially offending work (this is why Detective Conan had to be retitled for the US edition).
But I can name myself whatever I want to. And I damn well do. Auguste de Rivera is a character created by an anonymous /tg/ writefag sometime in 2010, and his anonymity does not affect his copyright in the slightest in the relevant future (50 years or date of death +50 years is still at least 50 years). Now, if I started a successful blog under that name and the character had been trademarked by then, I'd be in a bit of a pickle - but if I restricted myself to trolling galore under the same name OR writing, publishing and collecting money from a story featuring a character with that particular name, I'd be in the clean. The most the guy could do is spread bad word of mouth.
Which seriously doesn't help. Look at that Loren L. Coleman fucker. Eh steals people's work and doesn't afraid of anything.
And this brings me full circle to the primary question. Loren L. Coleman has a big woody for the mary sue character Harlequin and uses one of Harlequin's alternate names as his forum handle. Now Harlequin is a douche that needs killing ASAP and LLC is a douche that needs being put in jail ASAP, so we're witnessing a great celestial conjunction of douchebaggery right there.
But what if I call myself Princess Washburn and start posting pro-nazi shit? Or use the handle Tilde for my usual commie propaganda? Both of these trolling feats aren't likely to make the original authors happy. It's only that Big Brother has OCD. A successful author can't go around monitoring people's conversations making sure no one "dishonors" his characters. What he will be eventually aware of is the fact that people (in general) are taking his characters' names as their own handles, with the necessary realization that people will be posting retarded shit, as befits their nature.
I have a plan to quiz people on that when I have more free time. If you for some reason (or on Google's whim) have found your way here and read through to the end (or just saw this final paragraph), feel free to comment, no registration required.