yes, this is true! then again, also keep in mind that ANY OBJECT you place on your window may violate your state's laws. there is a law in MA that you may not have ANY object of any kind (including stickers) on any of your windows unless the car came with it (yet MA forces you to put the inspection sticker on the front windshield
what hypocricy!). so in some states, the suction-cup mesh thingies may be illegal as well. whether or not states will actually enforce such a seemingly trivial law is another thing... they may never ticket anyone for these things, but who knows...