Sometimes you have a channel with a peer and you really don't want to have that channel with them anymore - maybe because they are flaky about connectivity or whatever, and they are offline when you decide you want to be done with them. You don't totally hate the situation, so you don't want to force close the channel, but you just want to close the channel next time they come online. This plugin is for you.
You provide the peer_id (pubkey) for that peer, and next time they connect to you, the channel will be closed.
$ lightning-cli effthatguy <peer_id>
[peer_id]
If you change your mind, you can clear the list.
$ lightning-cli effthatguy-clear
If you had a very long list, and want to remove a single entry, then presumably you had made some poor life choices, and will need to rebuild the list. PR's welcome to add that feature though ;)