Someone was doing that to my gallery pages. Only they were downloading page, hosting the page and trying to hotlink to the pictures on my server. Of course hotlink protection they only got a red x, but they didn't change my referral code and I did end up getting a sale from one of these hijacked pages. (amazing since there was no pictures on the galleries, lol, just red x's and sales text)
Still, I didn't exactly like the idea, but looks like they stopped doing it or moved on to someone elses pages.