It may or may not be OK to record without having a notice if your intention is a specific private use, like your own legal defense. It would certainly not be OK

It may or may not be OK to record without having a notice if your intention is a specific private use, like your own legal defense. It would certainly not be OK to publish a video clip of a specific person you encountered that may be embarrassing. For example, you can be fined for publishing footage of an accident where someone was hurt and may feel embarrassed that other see them in that condition, but it may be OK to give it to police or legal council of people involved.