Thanks for the quotes, JWFacts. As someone who was raised "from infancy" as a devout JW and spent decades in the organization, it was always crystal-clear to me that reading "false religious literature" or anything that argues a religious position contrary to what the WTS teaches was off-limits.
Perhaps a brief experience may best illustrate how Witnesses view literature that disagrees with their views. Some time ago, I had a conversation with a family member who is a long-time JW, regular pioneer, has been on many assemblies/conventions (demos/experiences, not talks, because she's a woman), and is an expert on WTS doctrine. At the time, I was having some concerns about whether the Bible is actually inspired. I told her that I was interested in digging into the issue by reading what the experts in the field had to say.
She told me that there was plenty of information on this subject on the WT Library CD. I told her I had read that material, but that I recognized that the WT material was severely slanted in one direction, and I wanted to read what the experts in the field had to say. I asked if there was anything wrong with that. She responded that Satan controlled the world, and thus I should be wary of such books. She also related the experience of a friend of hers who was having some doubts about the Bible, but that after really studying the WT literature on the subject concluded that her doubts were unfounded. She encouraged me to follow a similar course.
I replied as follows "So it seems like you're saying that it's ok to research this issue as long as everything I read is on one side of the issue. Anything that argues in favor of a different conclusion is from Satan and can't be trusted. Doesn't that seem a bit circular?" She acknowledged that it sounded strange, but that it boils down to faith.
In my experience, this sort of mentality is not the exception--rather it is the rule among JWs.