My son and I just recovered a scooter from a garbage heap here in D.C.
Because it was badly damaged and in the trash I didn't think about it possibly being stolen until I got it home and found that the lock/ignition had been drilled out. I'm turning it over to the police and hoping that the owner either recovers it or refuses it so I get salvage rights.

If you buy, make sure that bike has good locking systems. An ignition in a plastic body part just won't do. Also most seem to come with a stowage space below the seat. Look at the retaining bar on the seat and make sure it is decently thick, metal, and secured to metal not plastic. Otherwise one good yank and you can say goodbye to your helmet or any other items (including your gas in some models).

You might also want to consider a moped. Same speed and fuel economy but they generally don't fall under the motorcycle laws.