Too often, what seems like a fun collectible actually belongs in an archive. But for an object to make the transition from store shelf to archival box, someone needs to recognize its importance. As the Times Union’s Paul Grondahl reports, a rare Revolutionary War-era ledger was recently discovered on eBay—and thanks to a historian’s keen eye, it’s now safe in an archive instead of a private collection.

Tricia Barbagallo, a Colonial historian, found the documents when she randomly typed the search term “1772 Albany” into eBay, Grondahl reports. There, she found a Revolutionary War-era ledger from an Albany County justice of the peace that never ended up in county archives.

The sale was against New York state law, which requires that significant records be retained, not sold. Every state has records retention laws, though they vary from state to state.

Then as now, New York justices of the peace handled lower-level crimes and disputes and officiated marriages. The ledger offers a rare glimpse into New York on the brink of Revolutionary War. Matthew Adgate, the justice, was what historian John L. Brooke called a “powerful [fixture] in the politics of the new state” and was involved in resisting the Crown and drafting New York’s new constitution.

When Barbagallo alerted authorities, they investigated the seller, a Vermont dealer. Then they tracked down the private collector who bought the piece and the documents were turned over to the Albany County Hall of Records.

It’s not the first time historical records that should be in an archive were spotted on eBay. The online marketplace offers a tempting place to unload precious documents. As Smithsonian Magazine reported in 2008, a sharp-eyed librarian used the site to track down a thief who ripped hundreds of historic maps and lithographs from books in Western Washington University’s library. The investigation that followed revealed the scofflaw had stolen 1,000 or more books from libraries nationwide and ripped 20,000 pages out of other books. And in 2012, a National Archives employee admitted to stealing rare recordings and selling them on eBay. He was only nabbed after a radio historian saw a recording he had donated to the archive on eBay. The investigation that followed revealed the thefts of over 6,000 archival recordings, including one of the Hindenburg disaster.

In 2008, eBay agreed to buy back $68,000 worth of stolen items from the New York State Archives—thefts that Barbagallo herself spotted, but ended up reporting to the man who stole them. Only when a history buff saw other documents on eBay and reported them to the authorities was the thief caught. So before you click “buy” on that online auction, ask yourself whether a document belongs in an archive instead—and be sure to alert the authorities if you suspect it’s being illegally sold.