This is how people avoid it in Sweden. However, the stores are obliged to report in when you purchase a TV, but all of these things can be avoided by simple lies ("I gave the TV to my friend for his birthday"), and many do so.
The declaration - however - is legally binding and there are huge fines for breaking such a declaration. However, they must be able to prove that you do actually have such devices, by entering your property. In most cases, they don't really bother, though.