Theft from libraries of books, historical documents, maps and other materials from libraries is considered a significant problem.[where?] One study commissioned in the UK estimated the average loss rate of libraries to theft at 5.3%.[1]
In the U.S. state of Pennsylvania, the third conviction for library theft is a felony, regardless of the value of material.[2]
Library thieves, who may be staff or regular visitors of the library, risk being discovered if a book is found in the library catalog, but is missing from the shelves. To avoid this, some thieves also steal the corresponding catalog card.[3]