We see loads of posts on here about CF's (cheeky *). There was the one yesterday about a woman who invited herself to go for dinner and stay overnight during a pandemic, with the host having just go back from holiday. Then you freecycle something and you can some CF asking if you can deliver it to their house.
While everyone on MN seems to be enraged when these tales are told, statistically some of Mumsnet's readers must be CF's themselves. Do CF's know they are being cheeky but just don't care? Do they not realise they are a CF? Are you a CF?