Bit mundane I know BUT - I live in a two car ( at least) per household street. Parking is limited.
A new neighbour has taken to putting two cones outside their house to stop others parking there.
Unsociable - yes - but is it legal, and is it ok for one to move them if no other spaces are available?
This sort of thing can lead to street wars. You and your neighbours need to nip it in the bud before the new neighbour believes it has become acceptable and his/her right.
It is neighbourly to 'allow' it when a big delivery is due - furniture/large white goods - or a funeral cortege, but not day to day.