[jcparks]

Is this a state or federal law?

Because, as I remember, (could be wrong) among the "broadcast" liscensee's, there is a minimun requirement in the federal agreement to broadcast a certain number of hours per day of PSA's.

How the quality of the PSA is ensured, I'm not sure. (Actually, considering our government, quality is probably the last criteria accountable.)

[JLGALT]

You're correct about the number of hours required for PSA's but there is no requirement for accuracy. I once contacted one of the agencies that puts out a totally misleading PSA. They informed me that they have the freedom (interesting word considering) to place anything they want in the advertisement even straight out lies!