All locking and 4 wheel low are not intended for on road use or when the roads are dry.

read here: http://www.4x4abc.com/jeep101/engage-diff-lock.html

Also when you mix that with people who don't really know what theyre doing, thats double trouble.

 

just wow..............

 

Of course you shouldn't lock it on dry roads. Your posts suggested there was some reason to not lock it on ice / snow covered roads. I maintain there is nothing wrong with that. I guess best bet it to just read the owner's manual and come to your own conclusions, althought frankly, I think it's pretty clear.