I don't think there's much chance of getting people accidentally seeing apostate stuff, before the orginization goes online they'll be sure to drill into everyone's head what site to go to.
I also think it does really well for the quoting stuff because they can always just deny it and say someone either edited the literature on their own or photoshopped it to make it look worse for them. Plus if the library is only available online that makes it MUCH easier for revisionist history.
The only thing I would say is that for me if someone came to my door giving me a tract and said that the books and stuff was available online, I would think they were a pretty shoddy group. While Internet is a great source of information, everyone knows not to believe everything they read online, especially if there's no references along with it. I will say that is a double edged sword because if they do use references with an online document anyone could read the full quote, which will at least prove interesting for all the mis-quotes found in every publication.