This sounds ridiculous but I honestly wouldn't be surprised if it was true. While people stab MPs and blow themselves up outside children's hospitals, Prevent would rather focus on harassing normal, patriotic people.

I know quite a few people who've had a knock at the door for really silly things, like entering PA's baking competition a couple of years back.

If somebody knocks at your door, ask them if you're under arrest or if they have a warrant. If the answer is no, politely say "No, thank you", close the door and end the conversation there. You do not have to put up with harassment and intimidation from this vile organisation.

https://teleg.eu/s/TraditionalBritainGroup/7234