Brad Vice, the author who saw his career go up in flames over "unacknowledged use of source material" (something less charitable people call ...um...plagiarism) has discovered once people find out you lied about one thing, they go looking at everything else. And it turns out, of course, they found it.
Another guy who had his background looked at with zeal was the guy who espoused lying on cover letters, or puffing up your writing credentials. He had his own credentials looked at by the folks who hang out over at Making Light. I'd rather be interrogated by the IRS than have these guys after me. They're not only thorough, they're hilarious. And it's one thing to be discovered to be a lying, cheating scene stealer. It's worse to have them doing it with wit and style.
But the point of course is now that everything in the world appears to be up on the net, people WILL look. Plagiarism has always been wrong. Now it's just stupid.