The Draft EA for the Sand Wash gather plan refers to it in a section about record keeping for wild horse fertility control programs (bottom of page 22 in the pdf).
A web search pointed to a site called ‘WHIMS Web (AWHC).’ It is not a ‘dot gov,’ which would signify government ownership.
The warning message says “Actual or attempted unauthorized use of this system will result in criminal and/or civil prosecution” and “WHIMS Web reserves the right to review, monitor, and record all activities on the system,” which are “subject to review by law enforcement officials.”
Good grief, what are they hiding?
If it’s a database for wild horse darting programs on public lands, why isn’t it in the public domain?
Western Horse Watchers Association 
Is it permissible to share these articles blogposts with members of horse groups on FB and if yes, what method do you prefer?
The data base (third party) is proprietary. Any entity that subscribes to it has to provide a disclaimer to that effect. It’s more of a licensing issue with requirements set by the software company since there are so many hackers out there trying to steal source code. It’s a nuisance, I agree. However in conducting range rescue operations, the data base is useful. For example, if we’re asked to remove wild horses from a school ballfield, someone licensed to access the data base can tell us with precision where they need to be returned.