Nationwide alert for police forces?

BOSTON -- From Boston to Los Angeles, police departments are bracing for large demonstrations when a grand jury decides whether to indict a white police officer who killed an unarmed black teenager in Ferguson, Missouri.
The St. Louis County grand jury, which has been meeting since Aug. 20, is expected to decide this month whether Officer Darren Wilson is charged with a crime for killing Michael Brown after ordering the 18-year-old and a friend to stop walking in the street on Aug. 9.

So, goes the theory, nationwide large groups of African-Americans will form in protest threatening lives and property.   So who put out the alert? Evidently is was an outburst of preparedness from Boston to Las Vegas.  So we have four or five major police departments preparing in case large groups of African-Americans start threatening lives and property.  Well, let us see if large groups of African-Americans are that stupid, I would think not.