(CNN) The Department of Homeland Security is warning law enforcement across the country that a convoy of truckers protesting Covid-19 vaccine mandates, similar to recent protests in Ottawa, Canada, could soon begin in the US -- with the potential to affect Sunday's Super Bowl in the Los Angeles area and cause other disruptions. A DHS bulletin issued on Tuesday to state and local officials, obtained by CNN, said the agency "has received reports of truck drivers planning to potentially block roads in major metropolitan cities in the United States in protest of, among other things, vaccine mandates for truck drivers."...