You know, I never even thought of even looking for any kind of a libertarian club to join when I was in college. Of course, there's no booze allowed on campuses in my state, so there wouldn't have been any drinking unless we rented a party bus or went downtown in some kind of a convoy or something. No, my thing was the anime club, but I've found that there tends to be quite a bit over overlap between anime fandom and libertarianism. Hence the "defend waifu with raifu" meme.
There's already enough of the problem with things like private prisons which makes me really uncomfortable with private businesses having anything to do with enforcing any kind of laws. As it is, security companies are already kind of walking a fine line as far as I'm concerned, and should be more limited in what they can do, or at least more answerable for misconduct than they currently are. And when it comes to handling other things, it would just be adding another layer of bureaucracy, and make it even more difficult to address any problems, because it would become a game of hot potato between the contracting company and whatever government office contracted them as far as who was to blame.