It also depends on the contents and the intention of the video. If you take a video in The Mall for example trying to explain what a nice place and how frequented by people from all over the world it is, and a somebody happens to not like the situation in which you accidentally filmed him, he cannot claim you having tried to defame him and ask for compensation. He can only ask the video being taken down from the public area or his face blurred in the video.
Another question about that, please.
If someone has some photos or videos showing some people and sends them privately to a few friends without the permission of the subjects, would that be a problem?
Also kind of depends on the circle of friends and the videos and the purpose of distribution. If your friends don't backstab you and send them to the subject, attempting to cause you problems, you should be fine. If the person hacks into a private forum, your PMs or email and sees the photos or videos he also has to answer how he got that info from your private correspondence. And then it won't be easy for him to prove the purpose of the correspondence. For example if you send some photographically documented negative news about a person to your friends it could rather be information for the purpose of warning than defamation of that subject.
In another extreme it could be distributing pornography for example.