It's just in my nature to do it. What you may ask.
Snoop around on a wireless network to see what is open and vulnerable.
Now don't get me wrong, I don't do it to hack into systems. I do it to show friends and family that just because they have a router with a firewall protecting their network from the Internet, the need to also secure devices on the inside network is just as important.
I've been known to cause havoc on wireless home networks such as having their printer spew paper onto the floor, or easily log into the router and disable access because they were lazy with using a password that was their home address (or worse, never changing the default password).
The shock of what just happen catches their attention.
For that matter, who needs to be stealthy when you can walk around their house and press a key on the keyboard only to reveal the PC is not password protected (social engineering remains an easy method for hackers, just ask the NSA).