Do you owe another person an explanation for unfriending him on Facebook?

I'm "friends" with many people on Facebook who I can't stand and with whom I would never willingly spend time in real life. I've purged many Facebook friends I didn't really know and/or who've contributed nothing of value to my life, all for the better. Now I am considering whether to unfriend former lovers and one-time real life friends from my youth for a host of insurmountable reasons -- for example, our politics don't jive, I'm annoyed by seeing endless photos of their pets, and so on. Odds are I will never have any dealings with these people again, mostly because I don't want to. Do I owe them an explanation for the unfriending?