This is well done by Linode. Much better than this stuff that a lot of companies do:

Please select a password that includes a capital letter, a number, no two consecutive letters or numbers or common words, but don’t exceed 7 characters and don’t use any special characters either.

http://blog.linode.com/2012/04/05/linode-manager-brute-force-protection/

Related posts:

  1. Another password FAIL
  2. Password fails, continued.