It's obvious isn't it?
The cops needed something to. They were sick of eating donuts and sitting hidden under bushes on sides of the high way.
I can see it now..
15 innocent people peacefully eating burgers at a picnic table in a sunny country field. All of a sudden they hear the roars of a giant helicopter soar overhead. The Troops dive out of the helicopter with M-16s and storm into the party. The party-goers are stunned, they stare blankly into the faces of the nervous policemen who tell them to all put there hands up!
LOL, stupid Authorities.