This is called a "mapping exercise" (at least by my local Health and Wellbeing Board). They commissioned research to first find out who was out there, and then have a few "workshops" for groups that shared a common interest. To start the process is easy enough for the collective mind of the readers of this list. But to draw any conclusions would be harder.
"Open Rights Group" was one that popped out when I read the lists. I gave them as an example of an org that I left since the annual subscription was too high (£60) on this email list a while back when we were discussing the subscriptions (the fee for being a member the registered charity now).
Gordo