Did the Police Have the Right to Evict the Press?

Around 1:00 am this morning, police gave final warning to the Occupy Philly protesters to evacuate Dilworth Plaza, next to City Hall.

Before the police issued their final warning to the protesters, however, the police told journalists that they had to vacate the area and watch the events unfold from across the five lane street, probably 150 feet away from the entrance to the Occupy Philly encampment. From the press vantage point, it was almost impossible to see the actual protest site.

Did the police have the right to evict the press?

Were the police simply ensuring that journalists did not interfere with the police work?

Or were the police trying avoid a situation like that at the University of California, Davis, where video of a campus police officer pepper-spraying a group of protesters became a viral phenomena?