I find it unfortunate when someone uses the term “trolling” to refer to bad etiquette or even “pranking”. The word “trolling” emerged with a specific and useful meaning: to provoke a response, as if fishing for reactions. Bad behavior doesn’t necessarily make you a troll, it makes you a jerk. Some jerks may be trolling, but not all.
Likewise, not everyone who is trendy in a way that you dislike is a “hipster”.
There are a few types of semantic drift, and the one at play here is widening. By abusing the word, people dilute its meaning. If the improper usage spreads, the word becomes ambiguous. People no longer know exactly what you mean when you say it alone; you’re forced to expend more words to clarify your usage.
However, it is possible to turn the tide against semantic dilution and preserve the utility of the word. With a pithy comic or blog post, awareness of the improper usage can also spread like a meme.