One of the problems with trailer theft is no "sure way" to lock the wheels. Some members have resorted to chains through the wheels, tire locks, cables through adjoining wheels and some other solutions. One of the drawbacks was price of the tire locks, some are well over $100 each. A problem with them is that if you only use one, a thief can remove that wheel/tire and still tow your trailer on 3 tires.
Grip-on tools just introduced a "relatively inexpensive" (about $10 each) wheel/tire lock that secures the wheel to the spring behind it. This makes stealing the wheel/tire much more difficult and eliminates the possibility of removing one wheel and still towing the trailer on the remaining 3.
While I haven't seen these in action, it does look like a relatively inexpensive method of securing wheels to the trailer so they can't be stolen and also preventing the trailer from being towed.
The "new lock" is shown here in the first picture and the older type wheel/tire lock is shown in the following two pictures.
I have no interest in the company and have not yet used the product. Just posting about a possible "new alternative"....
http://www.gripontools.net/store/product.php?id=16167