It's not recommended to include images or video clips that show lot of people in your projects. Everyone is entitled to their right to privacy, even if they are in a public and very crowded place.
One might think that shooting a public place allows you to portray, in an unrecognizable way, the people who pass through it, but that is not the case.
If a person is recognizable in a photo or video, thier permission is required for that photo or video to be published.
If you need to shoot these types of scenes, you have to make sure that none of the faces are recognizable; otherwise you will have to provide the signed talent release of all those who could be recognized in the video.
Obviously there are some tricks you can take to do this kind of shooting without running into irregularities; for example you could change the scenes in post production, by blurring or accelerating them so that the faces are not recognizable.