jetski's toolbox - today: the most simple DIY wheel anti-theft nut

To be honest anyone that really wanted to could strip the thread or break an axle with a decent sized spanner or socket set so Pitlocks or similar that need a completely different shaped tool to remove are the way.

A long enough lever will brake anything. But then it's broken, which wouldn't be the discerning thief's choice.

BTW, in terms of Pitlocks, there is a tool on the market for quite a time now. It uses a circular honeycomb-arrangement of tiny movable pins at the tip, which opens them all.