A baseball bat of marijuana.
This really has all the makings for a terrible stoner comedy. The holy grail of joints has been captured by the evil cops, and it's up to three dudes (the overzealous motivator, the smarter yet more cautious guy, and the comic releif conspiracy theorist) to get it back. They'll pull through with some ridiculous loophole uncovered by dude number 3.
The joint, by the way, was filled with 2.5 pounds of weed. The event you see is UC Santa Cruz' annual 4/20 smoke-out.