On news reports, when they are filming a report in public and people are walking down the street in the background (faces showing), do the producers have to ask them to sign contracts to appear on TV once they are off-screen? Or are they "plants" and have already agreed? Or are news reports subject to some sort of clause that they are allowed to do this without contracts in the name of public interest?
(Before anyone asks, this did not happen to me - I'm watching the news right now and just wondered).