Its one thing when its "Tony is out of town, I will borrow his lawn mower and ask for permission later." Its completely different when you don't understand the implications of the thing you are doing.
I have been the "permission granter" thousands of times where permission couldn't be granted due to everything from in feasibility of the request [There are not that many widgets to give], prioritization [its not worth taking from the main product to feet your pet project], compliance [doing what you want will get us fined], to flat out legality.
Developers with this attitude RARELY understand the implications, even in a company of 20 people. They assume that they are getting things done but really they are just moving the problem to a team further down the stack.
Within a company, going around a permission giver is almost always a good way to be labeled a "dick" by the people cleaning up after you.