Is this an invasion of his privacy?
Of course it is, but when you're a public figure, even if you're not in public office, you expect your life to be fodder for the public. It may not be fair, but it is, I fear, part of the trade-off, especially when a person's fame evolves from preaching morality - or preaching anything. If you take a strong, public stand in favor or against something, you just have to expect that your life will be considered fair game for those engaged in the sport of icon-bashing. It may be too bad, but there it is.
