Ten years ago, I found one of them at my door. Or rather, sitting in his sedan on the road, waiting for me to come home. When I pulled in my driveway, he called out to me, "Are you (name)?" I was so surprised I said yes (don't think I would do that now). When he said he was from the census, I said, I returned the form and I'm not answering any more questions. He got all huffy and drove off.
Be warned, they are bold. They'll be out there waiting for you.