Hmm.... had my share of these guys lately.
Once i was moving around with my lion. I went close to a den, and a pack of 10 or so wolves "blocked" me from the den entrace. So, as i was bored, i went and started to RP. Its actually not as bad if you are bored and want a good laugh. In the end others joined on my side and the pack left the den, the leader guess (sorry for the word) "butthurt" that i wouldnt leave, and im still asking them to let me in the den to rest.
They said its a private RP, so they wouldnt like me there. I suggested they better make their own map, or RP in group if it is that private.... brains guys... brains...
btw
be careful guys. sometimes "den-claimers" are just RPing. ive come across many of these kind. they just want to spice up the boring RP with intruders, and wish for you to join. i was too first offended by these ppl, but then when i started to RP, i realized they too are just RPing, and dont mean harm.
In my free, boring time, i do like to go around the plains and approach every den to see how ppl would react. If there is no reaction, i leave, if they are harsh (like: gtfo wtf its our den! LEAVE!!!) then i stay and have fun... and watch them get furious, and curse their lungs out. Its fun. try it.