I mean this is cute but I think this might be the fourth or fifth implementation I've seen and they all have better likelihood of just annoying someone instead of educating them.
I realize a standardized alert message delivered via JS doesn't have the same "share-able" impact, but it's probably more effective overall.
I'm imagining Wikipedia's fundraising drives and whether they'd do as well if they just blurred out a large portion of every article to raise awareness versus a prominent message.