The most common grounds for arresting protesters are the Illinois statute and Chicago ordinance against disorderly conduct, and especially their respective bans against unreasonable acts that disturb others and provoke a breach of the peace. Examples of unprotected disorderly conduct that might arise at a protest include: blocking traffic; harassing someone by blocking their free movement in the public way, and then forcing them to listen to an unwanted message; fighting words; making noise in a residential neighborhood in the middle of the night; and disrupting a government hearing by standing and shouting in the hearing room. On the other hand, the vast majority of protest activity does not comprise disorderly conduct. For example, audience hostility does not transform a protest into disorderly conduct, as in the famous case of comedian and civil rights activist Dick Gregory’s protest at the home of former Mayor Richard J. Daley, or in the case of Karl Meyer, who was wrongfully arrested because his protest in Chicago’s Old Town neighborhood against the Vietnam War provoked a violent reaction.
Another form of disorderly conduct is failure to obey a lawful police order to disperse, in the immediate vicinity of three or more other people who are committing disorderly conduct. For example, if a crowd of protesters includes persons throwing rocks at the police, police may order the crowd to disperse. On the other hand, if there is no nearby disorderly conduct, a police order to disperse is unlawful, as is an arrest for failure to obey that unlawful order. For example, a few years ago when anti-war protesters in an orderly manner distributed leaflets and spoke to passersby next to a military recruiting booth within the Taste of Chicago, it was unlawful for police to order the protesters to disperse, and then to arrest the protesters for failing to disperse