We are in Union City, CA and we had a similar inccident take place here about 3 weeks. There was a white mini van with two males, one was driving very slow around the court while the other went house to house with a "cell phone" entering information as he stopped at each home in front of it. My husband asked him what he was doing here in our neighbourhood--he said that he was collecting data for the US Census Bureau and then, they left once they got to the corner..the male got in the white mini van and we saw them no more..I found this very odd..we had never seen this before and no visible ID on the male nor the vehicle. To me, it was very weird and I had an unsettling feeling..my gut feeling told me that they were not legit....but from another Federal organization. Now, I know who there were....thank you for the letter..it clears up a lot of concerns and doubts. We are moving out of Kalifornia to the mountains in another state..we do not have any guns here...but plan to up North.