I'm not sure of the general criteria for suspected links that are sensored but I'm sure 90% of links newbies will post or likely send through PM will be censored. I believe the admins put this up to avoid phishing and other scams and hacks that newbies on the forum try to pull off a majority of the time.

Similar to when you get a warning if a newbie PMs you. But I know there some links that are generally censored regardless of rank for example things like mixers due to their ban.