I don't think the San Diego PD cares about how highly ranked someone is on Hacker News. What's more, I don't think 99.9% of the SDPD has ever heard of Hacker News.
This doesn't change the fact that the risks of harrassment for a homeless person can increase (or also decrease, depending on details of the situation) if they become well known.
For example, a local business owner or homeowner could start their own private campaign of harrassment by making a series of reports to the police. This can even be done anonymously.
Edit: Also, people who live far away, and know her only as someone on HN, can find ways make her life difficult.
It's okay if you think I was being paranoid. I've already allowed as I was being paranoid. But I had my reasons.