really? most of the ones I have been too look like they hire the "should be marching for civil unions rally."
..........not that I have anything against that, but there is some truth in it.
My friend worked for them for like 4 years and was let go out of the blue back in 2004, he wasn't the only one. He ended up as part of a lawsuit with several other ex employees claiming that certain people in upper management had bias towards those who who were straight and male. He ended up getting part of $$$ in the settlement.
As Jim said, part liability, not always necessarily anti-gun. Every place I have worked at in Human services has a NO weapons policy, not because of an agenda but for liability. You got to imagine the liability insurance they have to pay.