A trigger warning is a notice posted at the top of an article that indicates that the subject matter may be disturbing, especially because it may describe abuse, molestation, and/or rape and people who have been victims of such may not want to read or to read with caution, in a place where they won't have to worry about their emotions betraying them.
The Not Rape Epidemic is an article for which trigger warnings might as well have been invented. I don't normally feel as though I need them, but it strikes me as a piece for which pretty much every woman might need one, and not a few men. That makes it important, because it doesn't disturb for kicks but to discuss something painful yet common, and all too real: a pervasive, passively-accepted environment of sexual harassment that might not be rape (hence the title), but certainly marches right up to it and shakes hands.
I dislike the term "rape culture," because I think it connotes a culture in which rape is openly accepted and rampant, which brings to mind Somalia. That's a rape culture, if anything is. But I understand the desire to have a word for both the physical and cultural environment which lends credence to victim-blaming, sexual threats as a particular means of punishing women for disliked behavior or speech, and disdain for or dismissal of anyone who broaches the subject of such as a need for concern. Someone who threatens to rape someone on the internet because of what she had to say may not be a rapist, but they are (obviously) part of "the problem." And the problem has many names. I'm going to stick with "sexism," because it's simple and encompasses a lot of things.
Anyway, go read the piece. If you're feeling stable, and are in a place where it's okay not to be if such a need arises. It aroused a lot of uncomfortable memories for me, and might for you as well. The comments are full of people sharing theirs.