The crux of the argument which comes up from the 'apologists' for this type of thing extends from a different understanding of the axioms of privacy to everyone

The crux of the argument which comes up from the 'apologists' for this type of thing extends from a different understanding of the axioms of privacy to everyone else. Let p(x) be a proposition that means that doing x is a violation of someone's expectation of privacy. Some people seem to assume that (not p(x)) and (not p(y)) implies that not p(x union y). In other words, the assumption is that if x is not a violation of someone's expectation of privacy, and doing y is not a violation of someone's expectation of privacy, then doing both x and y is also not a violation of someone's expectation of privacy. However, the 'mosaic theory' suggests that the above assumption is not valid - doing x and y individually might be perfectly reasonable, but doing both could be a violation of someone's expectation of privacy.