Those are clearly 4th amendment matters. No one was argueing that money laudering and terrorist conspiracies should be legal, rather the methods that the government uses to enforce those laws run afoul of the 4th amendment. If there is probable cause, a warrant can be obtained and the information obtained. But they have to first have the probable cause, they can't just "go fishing" for it.
Exactly. The problem for conservatives comes in finding a clever way to guarantee privacy for one area of life while denying it in another. Quite simply, they cannot have their cake and eat it too. The kind of invasive government they need to stop rampant buggery would also go prying into their bank accounts, gun safes, bookshelfs, etc.. Personally, I'm willing to let the neighbors carry on like crazed weasels if that's what it takes to keep Uncle out of my affairs.