Clearly authorities are concerned about Radical Christians crossing the border from Canada into the U.S. "Terrorism: 2nd closing of US-Canada borders in 5 days," from AGI, July 17 (thanks to C. Cantoni):
(AGI) Detroit - Last night, for the 2nd time in 5 days, the border between the US and Canada was temporarily closed.
Arguably the busiest of the long border between the two countries, the crossing between Detroit, Michigan and Windsor, Ontario was closed after a warning was received, indicating that there was a bomb on the Admiral Bridge. Five hours of searches with canine teams did not produce anything suspicious and the authorities reopened the crossing. Last Thursday a similar situation interested the nearby tunnel Detroit-Windsor.