ever tried to leave fenway or the garden with a beer?

in the past two days i went to a celts game at the garden and a sox game at fenway, and that reminded me of something that's been bothering me for years.  when the game is over, if you try to take you're beer out of fenway there's armed guards there with tasers to stop you.  well that may be a slight exaggeration, but there are lots of security people who make sure no beer cups make it out the gates.  however, at the garden there is nothing.  literally NOTHING.  i have walked out of the building with a beer many times.  once last year i carried my half full beer down the stairs, out the door, across the street, and waited in line for a few minutes to get into the harp until the door guy there stopped me from bringing it in.  so my question is, how is this possible?  how can one place care so much, and the other not all at?  it blows my mind. 

oh yeah, and i think that new sign outside the garden this year may be the dumbest/ugliest/most ill-fitted sign ever made.  it's only appropriate for the circus or disney on ice.