Did you see this story out of Houston, TX? www.khou.com/news/Fake-census-worker-invades-home-kills-owner-93242534.html
A man knocked on a door, pretending to be a census worker. Once he gained access to the home, he let two other men in and all three terrorized a family - eventually killing one person.
It happened around 2:45 p.m. on Saturday.
In the St. Louis area, census workers are going door-to-door in neighborhoods to catch up with people who did not mail their census forms back.
Here's what the U.S. Census wants you to know about the people who knock on your door: 2010.census.gov/news/pdf/10things_censustakers.pdf
The key points are that a census taker will carry an I.D. card and a canvas shoulder bag with the words U.S. Census Bureau written on it and the taker will not ask to come into your home.
I, personally, would call the local census office to confirm that they've sent a census worker to my door (before even unlocking it). Call me paranoid, but it seems like a good precaution to take after reading what happened to a family in Houston.