Yes, it could be useful remember sometimes just the site of a firearm can be a strong deterrent. While I generally would prefer something with a little more oomph I think a well placed .22lr can be an attention getter.
Exactly. I believe if the victims at the State Fair incident were armed and stuck a gun in any of those punks faces as they approached their vehicles most of them probably would have fled the scene in a heartbeat. If not, a few shots would give you time to drive away.