Also, you can "flag". But I think it's only reserved for taking down partisan politics and flamewars (or other politically unpopular posts in Silicon Valley's standards), not (and I think should not) used for other purposes.
But I guess there's nothing to prevent you from doing it anyway, the guideline says,
> On-Topic: Anything that good hackers would find interesting.
> Off-Topic: Most stories about [...]
So yeah, feel free to flag, it's not abuse. The automatic threshold rule and the moderators have a final saying.