People from around the world were there to cheer and shake the Wal-Mart squiggle (the ceremonial twisting of the hips that is a part of their Wal-Mart cheer).
Market technicians never like to be wrong for more than 15 minutes, so Joe detected every squiggle in the market and fired off snappy teletype messages to the brokers throughout E.
The article also includes several quick and easy tips for defeating several security measures, none of which would be news to any actual terrorists, who are very likely capable of (for example) using Photoshop to make a boarding pass complete with the little squiggle on it.