In certain seedy parts of the internet, trap is a semi-pejorative term for a young, pretty pre-op trans girl. It spawns from imageboards focused on posting risqué images or outright porn, and the origins within there should be pretty obvious -- the beautiful girl is a "trap" because her offending anatomy is concealed until a certain point, after which people have a Crying Game reaction (vomiting). Except in this case I think the majority of these people were doing so ironically, because the topics with these images were always popular and I'm sure the same people kept coming back for more every time.
Entire new imageboards started that were dedicated to traps, with the joking disgust reaction getting seeped out of it. And since the pretty trans girls being called traps were themselves parts of these imageboard communities and using the terms for themselves, it kind of lost its offensive connotation altogether over time... within those communities, at least.
I lurked some of these imageboards as a young teenager. For me, seeing how beautiful these unfortunate girls became was a massive inspiration, and many of them had really hardened personalities -- either for better or for worse. I admired their strength to persevere through the tough times they were constantly talking about, and I loved the advice they gave to other people who wanted to transition. They were more real than any other trans people I'd heard of; they made transition seem like something I could actually do.
Of course, these communities only worked because most of the trans girls involved had very low self esteem and leeched confidence from the anonymous masses: teenage guys looking to jerk off. They were inherently degrading websites and it's weird that I'm writing something so positive about them. But I feel like I can justify it, because it seems like most trans people have an offensive thing that got them interested in transition.
Many times I've seen younger generations of trans people, people like me, get scolded by older generations for not understanding transgender history. A lot of people my age hate drag queens, often crossdressers in general, because they think that those people give other gender variant people a "bad name" in the cisnormative public eye -- but older generations remind us that many trans women started as drag queens, or crossdressing performers of other sorts, and that many homeless trans people have found shelter and comfort with people from the drag community.
Unfortunately I can't pretend to know a lot about these sorts of things, because I wasn't (and am not) there. But the parallel I'm drawing is obviously this: Since we live in a transphobic society, it's perfectly natural for trans girls to discover themselves with transphobic things. It's important for us to try to unwind how these experiences might affect our self-image, but it's also important not to blame ourselves for doing things that may have been offensive in the past. We're a product of our world, which teaches us to hate ourselves.
And that is why I can simultaneously think that traps are awesome, and traps are terrible. I don't like what the term obviously implies about the people it describes, but I have a lot of fondness for people who self-identify as traps. These communities meant something to me. At the same time, I envy a future generation of trans kids that might have better role models so they don't have to think about things like this. Maybe having trans women like Janet Mock and Laverne Cox visible in the media is the first step to being there.