it depends on which nuke you use. nuke evolution and phpnuke platinum are rock solid with sentry in place. I used phpbb and had a million hackers,spammers. I have 65 site 55 are phpnukeplatinum with video ,music,games etc. try going to http://learnphpnuke.com
. Havent been hacked yet, they try and get banned immediatly.
plus it beats this flat sheet look.