They're everywhere!
OMG! I rode the Cape Cod Canal bike trail yesterday mid-morning and encountered every genre of offenders on first leg of the trip.
I even had a bicyclist who had dismounted, left his bike on the opposite side of the trail and literally crossed right front of me, forcing me to swerve to the right (where thankfully there happened to be a side road to turn on.). I am not a fast rider by any means, but there is no way I could have stopped to avoid hitting him.
Thankfully, the ride back was much more enjoyable.
1990 Univega Alpina/(stock) gel saddle
2009 Specialized Dolce Elite/BG Lithia saddle
2009 Jamis Coda Sport/Selle Royale Respiro saddle
2010 Jamis Aurora/Jamis Touring Sport saddle