yes some are whitelisted, some are protected with a password and so on...
Things that even shouldn't be possible... I just ask me where they get their servers... On Vilayer I don't even have any of this options.

Thought to play dayz a few days ago, joined 4 servers, all gave me a whitelist kick. Closed game.

Hello,

We do report the servers that we run into of course, but please don't forget that all players are able to report abusive server admins directly to the GSPs as well:

http://forums.dayzgame.com/index.php?/topic/158966-dayz-standalone-server-hosting-rules-server-reporting/

Regards,
JStewart