@Nicolas Well if someone miss-click, then that is a misstake and if i was that user doing that i whould probably live with that misstake and whatch out next time, or talk to the admin change it with good reason for that. But if you choose to like a post, then you have made that choice, doing that like and would not be able to unlike it (as an option)
My big wish is to have likeingsytem related by optional weekly/monthly ranking and the most liked for example 10 users in a list as widget. And they will got medals for that (gold, silver and bronze ...) And if you got for example 2 gold medals for 2 month first place liked user. You got one gold medal at your profilepage with a "2" related to that medal.
But that whould be an other story offcause