Stalking

[rozmercer]

Is it legal for someone to stalk and film in the street?

[Peter Pedant]

No - the prevention of harassment law applies on the street
complain to the police soonest

that means you go down to the police station or ring them up and say so and so is harassing me....

and they take it from there.

[Peter Pedant]

filming - not sure about

It is legal to photograph or videotape anything and anyone on any public property, within reasonable community standards. Photographing or videotaping a tourist attraction, whether publicly or privately owned, is generally considered legal, unless explicitly prohibited by a specific law or statute.

Used to be a big thing, but now everyone recognises that we are the most video'd country in the world. Think novichok. There are 5 cameras in Red Square but when the Russians walked up Wilton Rd Salisbury which I know from 50 y ago they were caught on multiple shop cameras.

As for being harassed BY being video'd see the police
Clearly sometimes it will, and sometimes it wont