Well, so is an adulterer.
There was a gay man that worked in the security part of my old company (TRW). He was great!!! He took security very seriously, and did a great job.
There were plenty of heterosexual men and women that took security very lightly, and the company had some serious problems because of these people.
I'd rather have a gay person that takes security seriously, than a straight person that takes it lightly.
Where was it that you worked?
It has been 20 yeas since I worked in security, but as I recall, both adulterers and closet homosexuals were grounds for security clearance dismissal.
I suspect adulterers are undesirable as well, for the same reason.
The point is not their orientation, which has no impact on performance - the point is if they are in the closet they are subject to blackmail.
This is as old as the hills, and well understood by anyone knowledgable of the topic. AP just kissing Gay butts again. It's not a "gay thing" - its a blackmail thing.