1) Inability to set virus scan to manual (apparently this hasn't been corrected even in the latest release)
2) An unethical "subscription" service with updates coming out with alarming regularity (strangely sometimes within a few hours of a "virus" coming out...)
3) Difficult and costly access to technical support, difficult to get responses to technical queries via e-mail.
4) If live update is in manual mode the user is not notified that updates are available.
5) The whole system runs slower with Norton than any other AV software i've ever used.
6) Norton sometimes quarantines essential system files without notifying the user (the only clues are the catastrophic system crash..)
7) Being as its probably the most widely used AV software (fcuk knows why) there are types of malware out there that specifically target and disable Norton software.
8) Certain conditions can mean you are unable to remove Norton - you have to download another piece of software from the Norton website to uninstall the software under certain conditions...
9) It costs money and there are better, free alternatives out there.
NB: Not all Symantec software is poo, Ghost was an excellent piece of software..
Just do a quick Google to see what the world thinks of Norton Anti virus