He is probably harmless and looking for attention. I think in the old days he would have been a goth, and this is as close as he got.
I agree with you here, especially if he is younger... I think all he needs is some positive reinforcement on his technical achievements and knowledge.. He is probably just a confused kid, but if he is hanging out at hackerspaces then he is on the right track. In those environments there are a lot of geeks and weirdos that are proud and cool, I think this kid just needs to find his own voice. I know it took a lot of trying too hard in different areas to find where I fit.
I also bet this kid is a super nice sweat hearted person, he is trying to display the opposite to hide his inner self from being judged my others.
And for you... if you want to hang out in hackerSpaces... be ready for all types of really weird people, and be able to look past the person and into the technical knowledge and what their goals are and how both of you can get closer to your goals.. and come on its a hackerspace... make a stungun (just a cap that discharges fast), being electrocuted is much more in the makerspace aesthetic of weaponry (its also interesting they work in the body... causing white blood cells to freak and body goes into diabetic shock due to high voltage (low amperage)). I have seen makerSpace groups with badges for building your own tazer and letting someone else use it one you...