The government permits the men to stay by the railroad tracks because the government does ot think that their small faction of memorized book pieces ca do any real damage to the society as long as they stay out and don't go around quoting pieces of their books. The men are quite fascinated by Montag because they cannot remember a time when a dissident was given so much attention. Perhaps it was because Montag was an intricate part of that checks and balances system that stifled and destroyed books and he managed to break away therefore weakening the system. As long as the men by the railroad tracks stay out of everyday life, the government allows them to stay there. The government does not believe that a few men are going to be able to have an impact on literature. They do not believe that several memorized passages and books can undo the work they have done to destroy literature and everything that goes along with it.