People are, of course, entitled to a reasonable degree of privacy but every aspect of daily life involves some sort of trade-off between publicity and confidentaility. People in ice cream vans should know this better than most. After all, they occupy an almost unique place in British life. if you carry your produce into a public place in an attractively-painted vehicle covered in slogans describing that product and imploring any passer-by to stop you and try it, and furthermore if you equip said vehicle with electronic chimes to ensure that nobody in the immediate area can remain unaware of your presence, you could fairly be said to be not so much a privacy-seeking citizen as the occupant of an actual advertisement on wheels and you are therefore entitled to the same freedom from public scrutiny as a bloke wandering up and down Oxford Street carrying a placard pointing out that the end of the world is nigh. Or a town crier. None.
Now give me a ninety-nine. Unless, that is, you don't wish to be disturbed.