Yep all you need is a Van or truck and if your Grom is locked up all they do is use a couple of those cheap roll away dolly or car movers from HFT and push it to their van/truck and cover it with blue tarp/blanket/sheet and drive off.
I had my 1989 GSXR stolen from my apartment in Sunnyvale Calif and I had 5 locks on the bike, a U-lock, GSXR key/steeering lock/front dic lock/chain going through my rear rim and chained and locked to a pole that had electrical wiring going through it and also the GSXR was covered. First indication something was going to happen was every evening when I got home from work my bike cover was off or moved some how on the bike. I assume they were casing out the bike on how to steal it. When they stole it at around 2am in the morning the neighbors heard banging and looked out the window and noticed 4 guys working on my GSXR and the neighbors called the Sunnyvale Police dept.
The police dept had setup a road block around my apartment complex and with their police dog was able to catch the thief and his gang. This capture solved 20 stolen motorcycles in the bay area.
Oh the thieves cut all my locks using the cheap ass cutters from HFT plus the hydraulic cutter and slam/jim unit to take out the GSXR EG key assembly unit and us a screw driver to start my GSXR.