SOLVED: Sci fi, read ~2000s, child in dystopian militaristic society. Spoilers.

[Karen]

Hi, all! I don't remember much about the book, except there was a kid in trouble in an authoritarian society, possibly communicating with a sympathetic person by radio.

It turns out that the kid is actually a spider-like alien. The person he is communicating with is a human in space who goes to help...?

Really, that's all I remember!