Recording the police doing their job in public in generally legal and is a protected First Amendment activity. Courts keep ruling in favor of recording police. Laws prohibiting it are not constitutional.
>Openly recording the police is prohibited in two states - Illinois and Massachusetts
No, not really.
http://reason.com/archives/2012/04/05/7-rules-for-recording-...
Last week the City of Boston agreed to pay Simon Glik $170,000 in damages and legal fees to settle a civil rights lawsuit stemming from his 2007 felony arrest for videotaping police roughing up a suspect. Prior to the settlement, the First Circuit Court of Appeals unanimously ruled that Glik had a “constitutionally protected right to videotape police carrying out their duties in public.” The Boston Police Department now explicitly instructs its officers not to arrest citizens openly recording them in public.
The law in 38 states plainly allows citizens to record police, as long as you don’t physically interfere with their work. Police might still unfairly harass you, detain you, or confiscate your camera. They might even arrest you for some catchall misdemeanor such as obstruction of justice or disorderly conduct. But you will not be charged for illegally recording police.
Twelve states—California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania, and Washington—require the consent of all parties for you to record a conversation.
However, all but 2 of these states—Massachusetts and Illinois—have an “expectation of privacy provision” to their all-party laws that courts have ruled does not apply to on-duty police (or anyone in public). In other words, it’s technically legal in those 48 states to openly record on-duty police.
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Fortunately, judges and juries are soundly rejecting these [anti-police recording] laws. Illinois, the state with the most notorious anti-recording laws in the land, expressly forbids you from recording on-duty police. Early last month an Illinois judge declared that law unconstitutional, ruling in favor of Chris Drew, a Chicago artist charged with felony eavesdropping for secretly recording his own arrest. Last August a jury acquitted Tiawanda Moore of secretly recording two Chicago Police Internal Affairs investigators who encouraged her to drop a sexual harassment complaint against another officer. (A juror described the case to a reporter as “a waste of time.”) In September, an Illinois state judge dropped felony charges against Michael Allison. After running afoul of local zoning ordinances, he faced up to 75 years in prison for secretly recording police and attempting to tape his own trial.