The 2007 JK's and up to some production point for the 2008 JK's have steering wheel locks that engage when the wheel is turned 180 degrees with the key removed. After some point in the 2008 production run, the steering wheel lock was discontinued, I'm told.
We tow our 2007 Sahara behind our motor home and have to run with the key in the accessory position to defeat the lock. We also have to pull the IOD (ignition off draw) fuse in the fuse box to keep the battery from draining while towing all day.
Wish I had a 2009 or newer some times, so I could eliminate this step when setting up to tow. I asked my service center folks if they could/would remove/disable the steering lock in my Sahara and they said they could get in trouble with the Feds if they did so??? Oh well.