Randomly Saved Files on my Hard drive

I'd been getting low memory notifications on my MBP so I decided to sift through my hard drive and delete some stuff. I ended up finding a ton of randomly saved photos and other files. Some I recognized from articles I had read or facebook profiles I'd looked at, but a lot of them, including a lot of porn, were things that I had never come across. They seemed to have been saved over a broad timeline, too. I'm the only one who uses my this computer.

Any idea how this stuff got on my computer, and how I can get it off without having to carefully pick through them to keep the stuff I did want saved?

Are you low on memory or hard disk space? If the former, try closing some applications to free up some memory. If it's the latter, cleaning out old content is the way to go.

As for the content, it must have shown up when someone was using your computer at some point. Regardless, you'll want to be careful when selecting things to delete. Have you run something like OnyX to clean up some old cruft?