Take a book, leave a book. Public bookshelves are appearing across Germany on street corners, city squares and supermarkets. In these free-for-all libraries, people can take whatever they want to read, and leave behind anything they want for others. There is no need to register , no exact date to return books and you can take or give as many as you want.  "It is aimed at everyone who likes to read--whatever age or education. It is open for everybody," said Michael Aubermann, a 44-year-old who works in IT management. "We put up our other outdoor shelves last year and it's been working really well," added Aubermann. The public book shelves, which are run with the money given by and cared for by local volunteer groups, have appeared independently of each other in many cities across Germany including Berlin, Hannover and Bonn, and also in suburbs and villages. Each shelf holds around 200 books and it takes about six weeks for a complete turnover, with new books taking the place of all the old ones, he said. While most of the shelves have so far been put up in rich neighborhoods, Aubermann and the 20 volunteers who help look after the project   are planning to put up future shelves in poor neighborhoods, where people often don't have such chances to read. So far, the Cologne book group has had few problems. For example, a used-book seller once emptied every copy on a shelf to sell at a market. Besides, book stores and online book sellers have their own ideas about free book exchanges. Who are allowed to read the books?
All the people. Only educated people. Those who live in rich neighborhoods. Those who have reached a certain age.