43% (not the majority) of all runaways report that physical abuse was experienced before leaving their home.

And even if this is not the majority it is a large %. But even here it only sounds to me like another reason to find them so we can get to the bottom of it (if the parents actually look for them and want to pay for a bounty to find them). And parents who abuse their children are not likely to put up huge bounties to find the child (just to repeat it). Looks to me like the concern is overblown on this.

The way the community uses it however is up to the community--which will be filled with people (like you) who actually care. Will there be some people who are not found? Id imagine so. Are there going to be some abusers who use this to find children they lost? I am sure someday there will be cases when it happens. However if it becomes used primarily for the wrong things I'm pretty sure we have a blockchain where the criminals gave us ridiculous breadcrumbs...and the people who are searching for missing persons/children will eventually pick up on the patterns of abusers. Which in my opinion makes anyone who abuses this system pretty dumb...especially when we could have a separate chain to catch people committing various crimes using the same tech.

In short: do something blatantly illegal and financially costly on the chain? Be my guest.