In March, something a little similar happened to me on our local bike trail (
http://www.bikeforums.net/showthread...ighlight=vicki). Since March, I have just stuck to riding in my 100-acre-woods and on the farm roads around my place.
I have kept on the police, however, until they have successfully cleaned up the trail. At least there have been no other incidents reported. In the meantime, I have bought some mace to take with me if/when I ever ride the trail again. I also plan to take a self-defense course at the Rec Center this summer.