Members of the Occupy and Anti-NATP movement meet police officers on Michigan Avein Chicago on Saturday, May 19, 2012.

Members of the Occupy and Anti-NATP movement meet police officers on Michigan Avein Chicago on Saturday, May 19, 2012.

 Members of the Occupy movement march from the  Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

Members of the Occupy movement march from the Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

 Police scowl at members of the Occupy movement as they march through the streets of Chicago on Saturday, May 19, 2012.

Police scowl at members of the Occupy movement as they march through the streets of Chicago on Saturday, May 19, 2012.

 Members of the Occupy movement march from the  Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

Members of the Occupy movement march from the Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

 Members of the Occupy movement march from the  Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

Members of the Occupy movement march from the Petrillo Band Shell on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

 The skies open up and rains begin to fall on members of the anti-NATO movement meet cops in front of the Art Institute on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media

The skies open up and rains begin to fall on members of the anti-NATO movement meet cops in front of the Art Institute on Sunday, May 20, 2012. | Brian Powers~Sun-Times Media