Flickr provides a function for pro users that allows you to view the referrers to your photos/photostream over the past two days (at any given time). I think it's interesting to get an idea of what people are looking for when they stumble upon my photos, and where they're coming from, so I'll browse the referrers every now and then. I particularly like to look at the search terms people are using to find my photos. I sometimes find them to be rather amusing.
As a sexually liberated erotic artist, none of the search terms concern me. I know that other people might have a problem with people coming across their photos looking for porn, but since most of my work is erotica, that doesn't bother me (on the contrary, I enjoy indulging people's sexual desires through my photography). But even were that not the case, I think it's important to have a level approach towards one's work, as an artist. I've written about this before, but you can't control your audience's reaction to a piece of art. To use an example that probably occurs constantly: if you take a picture of a pretty girl, and are offended by sexuality, you might be bothered that someone found that picture looking for images of pretty girls to pleasure himself to.
Okay, you may think that's sick, but if you're not being harassed or getting comments you don't like, then it's really not a problem. And furthermore, there's really nothing you can do about it, because it's going to happen whether you know about it or not - and the only way to prevent it is not to take/share the picture in the first place. And I have actually heard arguments against photography (or internet sharing) for just that reason, but my stance is that no real harm is being done in most cases and nevertheless, not taking or sharing any pictures at all is not a satisfactory sacrifice just to keep some people from "perving" over them.
At the bottom of the stats page flickr offers a link for those who are concerned about the search terms that are popping up - but the solution is, essentially, that there's nothing you can do about it. Except relax and not take things so seriously. People often get to your photos by the means you expect them to - for example, most of my photos are nudes and are tagged with the term "nude" so that people who search for "nude" photos will find them; and they do. But, it is inevitable that people will find your photos in ways that you didn't intend and could never have anticipated.
For example, I recently discovered that somebody had come across my photo Passing The Time [description: an illustrative photo of a nude man standing in front of a computer screen, pleasuring himself to a video of three people engaged in sexual intercourse] as a result of searching for "beast sex". The photo has absolutely nothing to do with "beast sex" or bestiality of any kind. But I was discussing sex in the description to the photo, and I happened to make a reference to the phrase "beauty and the beast". Hence, it turns up in a search for "beast sex". Now, upon discovering this, was I alarmed about creepy predators using my photos to fuel their disgusting desires for sexually violating animals? Nope. On the contrary, I almost doubled over in laughter when I saw that search term come up in my referrals.
Any other reaction would just be taking these things too seriously. First of all, you can't predict a person's motivations with such vague evidence. You don't know that the person who typed this search query is a dangerous psychopath, or if it was somebody researching sexual deviance, or just some bored guy trying to play a joke on a friend. There's nothing criminal about curiosity. And the day we start prosecuting people for search queries is the day that freedom of information is dead.
Furthermore, even if the person in question is a sexual pervert, turned on by animals in a way that polite society would deem unquestionably disgusting, and possibly criminal - even if we could know this for sure (and we can't), we still can't extrapolate a person's sexual desires to their behavior. Sure, one could argue that sexual desires are a good motivator for sexual behaviors, but it's not the only factor. Do we have nothing to say about fantasy? I'm turned on by Japanese tentacle rape [link to Wikipedia article] hentai, but it doesn't mean 1) that I'd force women to be raped by octopi in real life, nor 2) that I would even want to, or if I did, that I would actually enjoy it. Even what sexual desires I may have that are socially deviant do not, however, make me out to be some kind of dangerous criminal. Far from it.
Really, what this seems to come down to is people getting grossed out by sexuality, and making a whole lot of assumptions about people based on their sexual appetites. I'd tell you to just let it go, but you might complain, "what about the bad guys, I can't just let them go." All I can say to that is, you can't catch 'em all, and it's not fair to "shoot first, ask questions later". I'm not implying that criminals should get any leniency, just that freedom is more important to me than safety. People deserve to have the benefit of the doubt. And if you disagree, and think that life would be better under lock-down, with everybody suspicious of everybody else, and cops patrolling the streets (and your homes) 24/7, then you and I are at odds.