A SFWA Mystery

A friend pointed out to me that SFWA’s activities at Denvention 3 are posted on the group’s website. And after the listing for the SFWA business meeting there’s a note:

(Please come – we need a quorum! Discuss new By-Laws, 2009 Nebulas and more.)

Would they know if nonmembers tried to crash a SFWA business meeting? Or is it as unnecessary to worry about that as it is to try and prevent nonmembers sneaking into a WSFS business meeting? Both are a form of torture no person would inflict on himself if he had a choice.