Hirschgarten! That's pretty close to where I live! They serve Augustiner Bier there. One of the better beer gardens in Munich.
The militant-looking guys are the infamous Bierzelt-"Security"; the idea seems to be to hire the worst crooks and troublemakers to pose as "security" during Oktoberfest. Most of them are a bunch of incompetent, overagressive morons...as long as they're up against people smaller than themselves; I once saw one actually choking a teenage girl (not for long, though

. I was there with some friends who happened to be off-duty cops). One rarely see them getting involved in a real brawl involving the big, tough guys, though. You know, actually doing what they've been hired to do.