Msg#: 4642361 posted 11:09 pm on Feb 10, 2014 (gmt 0)
Interesting reply from one person/entity;
Default policy on our web filtering system. All unknown domains registered in the last 14 days. It does require us to manually unblock new legitimate sites being set up by marketing, but frequently catches the embedded URLs of the SPAM campaign du jour. Attackers will no doubt adapt accordingly, but for now it is a useful tactic.