On a larger scale, independent activity was expressed through underground writing and publishing. Because of the decentralized nature of underground writing, it is difficult to estimate its extent or impact. Some observers state that hundreds of books, journals, essays, and short stories were published and distributed. In the mid-1980s, several samizdat publishing houses were in operation. The best known was Edice Petlice (Padlock Editions), which had published more than 250 volumes. There were a number of clandestine religious publishing houses that published journals in photocopy or printed form. The production and distribution of underground literature was difficult. In most cases, manuscripts had to be typed and retyped without the aid of modern publishing equipment. Publication and distribution were also dangerous. Mere possession of samizdat materials could be the basis for harassment, loss of employment, and arrest and imprisonment.