All I can say is that IH predates the terrorist hunting work of homelandsecurityus.com and homelandsecurityus.net as far as being organized to solely post translated messages and documents. It probably predates 7 Seas. It doesn't predate the work of some of the key players in all of these groups, some who we know have worked with terrorism throughout the '90s or longer.
The messages and materials are and have been obtained from the same sources on the web. Think about it.... Don't NEIN and Jill both post messages? Well, IH began this way right after 911.
And some individuals doing this work originally hailed from IH. Some also have contributed to NEIN and other groups while also contributing to IH. Not all posters crisscross -- please be clear on this -- but some. It can be a small world and there is nothing at all wrong with that. ;)
This stuff is out there to be found by hunters. Posts can be pulled at the discretion of the finder and LEO. I do not believe it happens often, but it happens. If a finder questions a public posting of material, that finder will hold it. That probably happens alot. I would say Laura has been a very conscientious and careful poster. But she has a special talent since she understands the messages more than others, being versed in both the Arabic culture and language -- 2 parts that complete the whole absolutely necessary in understanding jihadi materials. Arabic is no romance language. Perhaps Aramaic is as complex.
The bottom line is that the key players mentioned here know what's what from monitoring for so long. They can identify potential honeypots and even possible disinformation on the part of jihadis themselves.
Considering the threat of legal action upon us should information from the source(s) you mention be used on FR, if people want to read those posts and access that information, they know where to find it by now and can go to that site for it, given the choices we all have.