Fractionals

That article is dated from a year ago, but I'm certain that it is even older than that. I remember reading something very very similar some time ago.

The article I read mentioned all the same points. I remember two key points from the article I read that aren't in this one.
First is that the current 'radioactive' symbol bears a slight resemblance to an angel with it's dress and wings.
Second is that any sign that so heavily suggests NOT looking, is most likely to only entice into digging for treasure. I mean, seriously. If we found a big ol' pit with a sign that says "Do not Dig, Dragons within" are you telling me modern man wouldn't start digging immediately?

I actually came upon this story at a post that had three or four similar stories linked; one started out with the 'angel' thing, so I imagine that's the one you're thinking of.

I agree about what we'd do if we found one of these, but there are two reasons I think it's a good idea anyway:

1. If society has become more primitive and superstitious (...not exactly unlikely), then this could actually work, or at least minimize the deaths; after the first couple of radiation poisonings they could stop rather than keep going.

2. If society is roughly the same, or more advanced, these warnings would hopefully at least make them more cautious, so that they would be the lookout for what might kill them.

But I mean, generally? Whoever finds this is probably fucked. Which is arguably our fault for fooling around with stuff that won't go away for millenia.