It’s kind of tricky to say that people can’t reclaim it unless it’s been used against them. The reclaimed use has become pretty ubiquitous.
And I’m sure I’m not alone in this:
Nobody has ever actually used queer as an insult against me, personally, either in real life or online.
I wasn’t out in high school, and I went to a reasonably liberal college, and I’m not particularly feminine but I don’t look like the stereotype of a queer woman. I’m not well-known enough anywhere online to get trolls coming after me personally, and the places where I talk about my personal life are reasonably queer-friendly. So being insulted by being called queer is not something I’ve ever experienced for myself.
Does that mean I shouldn’t call myself queer, even though my sexuality certainly does fit with what people generally mean by it when they reclaim it?
[I don’t use queer as my label, mostly because I’m not too invested in having a one-word label. But I do talk about “queer people” and “queer community” as things that I’m a part of, because it’s the simplest thing to call it.]