Last year, stoneshop, gummihuhn and I went to Finowfurt, Germany, on a nerdy version of summer camp. (Some of you may remember that.)
Since we were volunteering to help running things (they called us Chaos Angels... doesn't that sound nice?) I made several cardboard signs, telling people not to climb the bunkers, not to step on the fiberoptic cables or not to let their dogs (which shouldn't have been there in the first place) roam the site and pee on people's tents.

Now all of a sudden this picture of one of the signs I made pops up on a 'funny stuff found all over the internets' site, and is spotted by someone who then posts it on a motorcycling forum I read.
I never intended this sign for the internet. it was simply a sign, made for practical reasons, and I tried to make it a bit silly so people would notice it more and not think we were nagging about the rules.
This must be how memes are born.