Also, a quick search for radio stations using 90.5 FM in Portland shows there isn't anything broadcasting on that frequency in the area. The FCC regulates this both for licensing and to avoid signal contamination. It's not doing any physical or mental harm when it's being broadcast on an unused frequency in a range of frequencies that are designated for exactly the purpose of radio broadcast. The operators of this broadcast station, whether it is actually the church or not, are not causing physical or mental harm but they are ignoring the FCC regulations around licensing a particular frequency for public broadcast use.

Disagree with another's beliefs and viewpoints all you want, but let's try to avoid assigning motive and/or blame as well as spurious accusations where they are not due.