It’s an interesting point and certainly depending on what is posted and how it is represented there could be issues you describe, but that’s for posters to make their own judgement and there is plenty of advice elsewhere on the web. Obviously sending footage or pictures to police maybe some people’s preference or first port of call, but I’ve first hand experience of that going nowhere and not even being followed up when they said they would.
Unlike Twitter and all that stuff, from what I’ve seen here the posts seem reasonable and factual, though I’m no lawyer.
So if posters are asking for help, I think adding appropriate tags to help organise the information as helpfully as possible is worthwhile.