So I love a good parking thread (like most of mumsnet). But there's always at least one person who suggests penguin bollards. I just don't get it; I've looked online and they just seem to be normal bollards dressed up in iron like penguins but doesn't that mean the owner of the driveway won't be able to use it either if they're installed? Do they move? Are they just locked in place? Could someone please explain. 