Easily remedied. Get bolt-on skewers. They range from the simple hex-bolt variety (At
Amazon or have your LBS order them from JB Importers) to custom-keyed
Pitlocks. Between the two extremes are variations by Delta and Pinhead.
One caution about Pitlocks: The threads of their skewers are easily damaged. Replacement skewers are $11. But I've found using the skewers from the Amazon/JB Importers variety along with the nuts and shields from the Pitlocks is a reasonable compromise between security and durability.
I've had pitlocks for 6 years now and no issues. From my research they were the most secure of that type of security system. I'd recommend a pitlock or pitlock type system for any commuter that has their bike locked up for hours at a time.