Can you retransmit info from police scanners?

Anarchist arrested after tweeting out the fuzz to protesters – Ars Technica

The FBI arrests a man for Tweeting police locations during the G20 summit, and goes on to search his home.

I’m not aware of the case/legislation history on possession of police scanners, or regarding what information can be retransmitted, but is a troubling turn of events. Journalists, for one, are quite reliant on scanners to quickly get on location as stories unfold. Other than time and intent, it’s difficult to parse their actions from those of the tweeting protester. In First Amendment terms, going down the road of intent has been traditionally viewed as a slippery slope.

The author of this article closes by remarking that “Maybe it’s time for protest organizers to start moving back to lower-tech, less trackable methods of communication.” I would instead argue that actions such as these need to be challenged.