A petition...because they used quotation marks.
Sure, they imply that they're ignorant of the fact that being trans is "a thing" by doing that, but this reminds me of something someone (also trans) told me very recently: Trans people are way too sensitive. WAY too sensitive. And it's way too easy to step on our toes.
It's not surprising that there are people in media like that. But, chances are, if the author of that article is ignorant of trans issues, he's probably ignorant of all sorts of other things, too, and in that case trans people aren't particularly special. Maybe a petition for "No Ignorant Douchebags Writing About Crap They Don't Know About for The Daily Mail" would be more appropriate.
But needless to say, I think ignoring this type of stuff and not giving its author any unearned attention is the best policy, personally.