This allows developers to gauge user need for a particular enhancement or bugfix. As the Bugzilla user base expands, however, these thresholds must be re-evaluated. You should gauge whether this feature is worth the time and close monitoring involved, and perhaps forego implementation until you have a critical mass of users who demand it. This is confusing. Groups and Group Security Groups can be very useful in bugzilla, because they allow users to isolate bugs or products that should only be seen by certain people.
Groups can also be a complicated minefield of interdependencies and weirdness if mismanaged.
This way, they can have a fix ready before the security vulnerability is announced to the world. Alternately, you may create a Group independently of any Product, and change the Group mask on individual bugs to restrict access to members only of certain Groups. The only way a bitmask scheme can work is by doubling the bit count for each value. Thus if UNIX wanted to offer another file permission, the next would have to be a value of 8, then the next 16, the next 32, etc. Similarly, Bugzilla offers a bitmask to define group permissions, with an internal limit of 64.