The National Football League says its stadiums around the country "are very well protected" so a threat of a dirty bomb attack this Sunday is no cause for alarm.
The Homeland Security Department says it's very skeptical of a warning posted on the Internet but the seven teams named have been notified "out of an abundance of caution."
The message said trucks would deliver radiological bombs to stadiums in New York, Miami, Atlanta, Seattle, Houston, Oakland and Cleveland.
Minnesota linebacker Napoleon Harris will play with the Vikings this Sunday in Seattle. He says after Nine-Eleven, "you've really got to take everything serious."
Fans in Oakland won't see any noticeable increase in security, but the team's senior administrator says if they say they're going to do something different, "it wouldn't be security anymore."