In the case of people being shot, I find that just giving notice that the event is going to be video recorded is enough. Anybody on the witness protection programme will then know what to do.
And then there was
Tonight Live with Steve Vizard back in the 1980s in Australia. (Think: David Letterman rip-off)
Anyway, Steve's reporters would often do an unannounced live link to a local restaurant and interview whomever was there. Fairly straight forward, right? Well it just happened that there were plenty of bosses there with their secretaries having dinner at that time of the night. No legal action ever happened, but there
were complaints. :-P
There were also some pranks.
Andrew