Guys in early 20s who start trading firms - Stupid/Reckless or Confident/Smart? (just met some people)

I just got back from looking at office space in Manhattan for an internet startup a couple classmates are doing (I'm not really taking part - I'm more the PR guy. I still want to do finance).

Anyhow, the sales manager was showing me around the floor and let me take a 40 minute walk. So I did. I walked past an open office (about the size of a 2-bedroom dorm room) with 3 guys in there and 12 trading screens across the wall. I popped in and asked them what was up and they said they're in their early 20s, out of college (NYU Stern, Columbia, and Princeton) and they are doing daytrading.

I was like "well, why do you need an office to daytrade? Couldn't you do it in your apartments?"

They said "no we have to look professional"

Professional? So I asked them if this was a hedge fund they started or some sort of fund and they said they couldn't tell me. They also said about half the money they trade comes from their own pockets. They also said they do not come from rich families. This was during workhours (3PM-5PM) so I'm guessing they don't have a second job working for a bank or some other shit. This is fulltime.

Now, is this a smart thing to do? Has anyone actually done this before? They wouldn't tell me anything else (during the convo one of them even implied I was a competitor looking to spy them out LOL!)

Anyways are these guys reckless or smart? Can a bunch of guys in their early 20s really make a living from daytrading their own money? Anyone else done this before?