Okay, so here's a quick briefing on what's been done so far:
Called WTAE. They confirmed that they already had the info. Don't know whether that was from my email or if I was beaten on the phone by another Anon, but they're the ones who sent the 2/10 camera guy, so I'm optimistic about them.
Called KDKA. They gave me the proper email address for news releases (which was nowhere to be found on their website, from my searches at least): firstname.lastname@example.org
Called WPXI. They said they'd heard about the protest and took down my phone number.
Called the Post-Gazette. They gave me an email address for the guy in charge of local news on Saturday, and I sent him information.
Called the Tribune-Review. They also gave me the address of the person in charge of local news this weekend, and I emailed that address.
Also, got through to the South Side police, they seemed kinda busy, just took down the time and place and said thanks. They probably already know what's up, but so far no efforts to stop us, so that's a victory for Anon.