We're an ISV with ~65 customers. When they call with a support issue, we log it in our internal Bugzilla instance (there is a handful of specially trained super-users at each customer site from whom we allow calls).
We're considering making this Bugzilla instance available via the Internet so that customers can log their own issues and track their progress. However, we do not want any customer to see another customer's issues, not least because each issue can contain commercially sensitive information.
As far as I can tell, Bugzilla controls bug visibility using "Products" and "Groups". In our case, we'd have to set up over 60 of each, which would seriously complicate our usage and administration of Bugzilla (e.g. searching and reporting).
Is there another way to provide compartmentalised access to Bugzilla? Do any other issue-tracking systems have features that solve this problem?