As someone who has passion for sports teams in both cities (I'm a diehard O's fan first, Flyers and Sixers after that) I can tell you with certainty that Baltimore fans are uh...very mild compared to Philly sports fans.
I was at the Phillies-Giants game on Monday. The Phils got booed off the field because they were trailing 6-3 and sporting a 9-6 record at the time.
Philly fans...unique breed. Putting that nicely here.