How did authorities monitor library computer use by suspected bomb maker?

Wednesday’s news release from the U.S. Department of Justice, detailing a criminal complaint against a Michigan man accused of planning to make Molotov cocktails and bomb the Xcel Center, carried this paragraph:

The affidavit states that DePalma went to the Hennepin County Library on August 18 and spent 90 minutes researching recipes for explosive devices. DePalma produced a handwritten list of items he would need to construct “special” Molotov cocktails that would stick to people and other targets.

How did authorities get the information about Matthew DePalma’s activity while online using a Hennepin County Library computer?

“All I can tell you is what’s in the affadavit,” said David Anderson, a public affairs specialist for the Department of Justice. The affadavit didn’t say.

Did the library monitor, and then turn over, records of the computer’s use to authorities?” The Hennepin County Library and its employees had nothing to do with it,” said Stacy A. Opitz, a spokeswoman for the library.

That could mean it was something as simple as someone watching what DePalma was doing.

Under the Minnesota Data Practices Act, libraries can only turn over information about patrons with a court order. The Patriot Act allows monitoring of electronic (or other) activities of patrons in libraries,something to which the American Library Association has objected. Some libraries, according to the ALA, are destroying computer access records on a regular basis to avoid complying.

But in this case, there’s no clear indication how authorities monitored the library’s computer.