Something happened at Occupy Boston last night at about 1:30AM. 

We have news reports, video and photos, but we don't have a clear idea, those of us who are not in Boston.  

1. We know the police warned the occupiers to evacuate or be "subject to arrest."  

2. The police attacked, arrested about 100 people. Dismantled some (all?) of the occupation. 

3. Why? What changed? There doesn't seem to be any statement from the Boston police or city government. 

4. What is left of the occupation? 

Fresh photos would be welcome, as well as a report from an observer, someone who is neither part of the occupation or part of the police or government.  

Update: OpenMediaBoston says the arrests came after an attempt to expand the encampment to a second park.