I think (don't have a confirmed source to post) that all major sporting events were told by the government to up security at events this year. I say this because several schools have talked about increased security at games and NFL teams have been ordered by the league to do the same. In fact the Bengals are arguing with the city as to who pays for extra security. (http://sports.espn.go.com/espn/wire?section=nfl&id=2177973)
The oddest part is that my bag was cursory checked and my daughter wasn't even asked to open her purse at the gate we went in -- same reaction from people around us. This was the least amount of security at our gate that I have witnessed since 9-11. But others said they had their bags fully searched at other gates. We probably had a lax police officer in our line.