5 men were arrested for attempting to blow an Ohio Turnpike bridge that spans the Cuyahoga River here south of Cleveland. I'm on that bridge a couple of times a week on average.
THe perpetrators met and associated with others at "Occupy Cleveland" events. They were well known by some of the organizers (who were apparently fooled that these guys didn't really buy into the non-violent messages). Protest organizers, including one Cleveland Councilman, spent the day attempting to distance themselves from events, but also felt compelled to cancel their planned May Day activities as a direct result.
No question that movements like the "occupy whatevers" will be a lightening rod for fringe elements, such as these self-proclaimed anarchists. It would appear that extra attention paid by law enforcement, that groups rail against, is completely justified.