[hdbc]

Isn’t there some kind of substance that can be applied to your license plate that prevents these cameras from seeing/reading the plate? Someone should invent it, if not.

[voicereason]

Not sure about the legalities in any specific area, nor claiming the effectiveness of either, but here's a few examples:

License Plate Blocker Spray

These things have been around for awhile: License Plate Anti Speed Camera & Red-Light Traffic Camera PhotoBlocker