In this case, they're blocking out the Emergency Alert System of KBOO. Since KBOO is operating in HD mode, both stations were occupying the bandwidth between 90.5 and 90.6 MHz. KBOO is charged with providing emergency alerts for the immediate vicinity of the 90.5 pirate, but was compromised there.

EAS is expanding to provide visual alerts as well, which the 90.5 pirate fully blocked.

Worth pointing out here that KBOO is a non-profit community radio station, pretty close to the "public access" radio that people here are wanting.

Yes, I think a lot of people don't know what's available (or, at least possible) on their local dial.

It's hard to draw an exact parallel between public access on cable and public access on FM/AM.

Public access on cable is using infrastructure that cable TV companies were required to provide, as a cost for the privilege of using public right-of-ways to run their cables. All costs paid by the cable company.

None of that is in place in the US for radio. Each station has it's own transmitter and must obtain it's own tower space. There's no one to pay for the transmitter, tower and related infrastructure for a public access radio station.

The closest is the currently existing Low Power FM service, and the Non Commercial FM Service, but it's not free, like public access cable is/was.