My f-list is getting a bit too long to handle (mostly because of communities) so I've had to take a few people off. The main reason is because lately I feel like I'm watching the personal lives of people I really don't know that well (which feels a bit uncomfortable), or because I've had people on my list for ages but have never really got to know them, for whatever reason.
I tend to add back out of politeness or curiosity, which can sometimes be a bad thing. I'm not deleting because people don't comment or whatever, and it's nothing personal. I'm just having a bit of a clear up.