Why not believe it?
It isn't incredible that someone would take their computer into the bathroom to read or watch stuff, although I gather that you're more likely to be snapped when the laptop is on your bedroom desk / dressing table. You should remember the recent case of a lunatic U.S. school that set up computers that the children used at home to do this.
The other side of the coin obviously is finding these stolen pictures or videos being traded online, which I expect to be not difficult if they are there. On the other hand, the world also seems to be full of people voluntarily doing all sorts of things in front of webcams. Even attractive people sometimes. So these snatched screenshots and these cellphone pictures shot up ladies' skirts are pretty pointless. Just get someone to pretend to be filmed unawares while they check how much of the crumbs from those wafer cream biscuits went down their cleavage (it's amazing: I think those biscuits are mainly made from crumbs: you need a napkin or something).
I suppose that if I was hacking someone's computer anyway to get their credit card and so forth, and tapping the audio in case they read their password aloud, and I heard them start undressing in front of the camera, I might watch. Given that we're already assuming I'm a colossal sleazebag, which in fact I'm not.
Also, there apparently are very many cases where the naughty pictures are used to blackmail people into putting themselves in a much worse and more humiliated and abused position - including, again, alas, children, who are both sexy and gullible.