From the Pioneer Press: MnDOT says releasing bridge inspection records could be a threat to national security.
Before you dismiss such threats as implausible, note that Osama Bin Laden was trained as a civil engineer at King Abdul Aziz University of Jedda and Yasser Arafat was trained as a civil engineer at Cairo University. Since civil engineering would seem to disproportionately lead to terrorism [perhaps too much statics?], we should be very careful who we give our bridge plans to, they might actually be able to read them (as opposed to say, going to the bridge and looking for cracks themselves, or just getting more exposives).