Why do Jehovah's Witnesses decline to exchange their Bible study aids for the religious literature of people they meet? ... it would be foolhardy, as well as a waste of valuable time, for Jehovah's Witnesses to accept and expose themselves to false religious literature that is designed to deceive. ... it is out of wisdom and respect for God's counsel that Jehovah's Witnesses do not make a practice of exchanging valuable Bible study aids containing Scriptural truth for religious literature that disseminates error or apostate views. –The Watchtower, May 1, 1984, p. 31.
Excellent quote and one that I know of first hand. When I was about 15, I was working with my best friends' (fanatical) mother out in Serve-Us. I offered a woman at the door the Botchtower and Asleep! ragazines, and she said she'd read them if I would read hers. That seemed fair enough to me so I agreed. We hadn't got back to the car when Sister Fanatical took the literature that the woman had given me and threw it in the nearest garbage telling me basically what the quote above said. That always bugged me because I always felt that if we had 'the truth' that it should be able to stand up under any scrutiny.
On a side note: I had told my sister about 6 weeks ago that the Society was changing their interpretation of what "this generation" means yet again and that it now means an 'overlapping generation'. I guess they made mention of it at the ASSembly on the weekend which really irritated her. Another thing that bugged her was when they said "you shouldn't be listenening to anyone to says "Oh, I don't believe Armageddon's coming in our life time." For the very first time she said to me "It sounds like they're trying to control what you think."