Christopher Drew is a 60-year-old artist and teacher who wears a gray ponytail and lives on the North Side [of Chicago]. Tiawanda Moore, 20, a former stripper, lives on the South Side and dreams of going back to school and starting a new life. About the only thing these strangers have in common is the prospect that by spring, they could each be sent to prison for up to 15 years. The crime they are accused of is eavesdropping. The authorities say that Mr. Drew and Ms. Moore audio-recorded their separate nonviolent encounters with Chicago police officers without the officers' permission, a Class 1 felony in Illinois, which, along with Massachusetts and Oregon, has one of the country's toughest, if rarely prosecuted, eavesdropping laws. Before they arrested me for it," Ms. Moore said, "I didn't even know there was a law about eavesdropping. I wasn't trying to sue anybody. I just wanted somebody to know what had happened to me." Ms. Moore ... is accused of using her Blackberry to record two Internal Affairs investigators who spoke to her inside Police Headquarters while she filed a sexual harassment complaint last August against another police officer. Mr. Drew was charged with using a digital recorder to capture his Dec. 2, 2009, arrest for selling art without a permit on North State Street in the Loop. Both cases illustrate the increasingly busy and confusing intersection of technology and the law, public space and private.