Raw Story:

Liberal bloggers in New Hampshire busted an aide to Rep. Charles Bass (R-N.H.) who was posing as a liberal blogger on such blogs as Blue Granite, NH-02 Progressive and others. Bass' office admitted culpability to HOH and said the staffer would be "appropriately disciplined."

The unnamed aide to Bass - who, like many others in his party, faces a tough re-election fight - was routinely trolling liberal New Hampshire political blogs calling himself "IndyNH" and more commonly IndieNH, pretending to be a progressive.

Finally, after noticing that lots of things he said just didn't add up, a couple of the bloggers traced IndieNH's IP address to the House of Representatives. Read on...

This is just the one who got caught. I'm sure it's far more prevalent than just local race blogs.