Hi, all, From the regulatory side, but perhaps useful to bring to your IRBs attention--the Office for Human Research Protections has guidance around the use of social media specifically for clinical trials recruitment at http://www.hhs.gov/ohrp/policy/clinicaltrials.html I agree with Monica that asking for permissions from list owners is good practice and usually is not difficult to attain. (ANd I highly recommend Monica's article in IJIRE.) Also, having a site moderator or leader post a "sticky" or other note announcing the study on the top of a forum or on a wall, etc, is good entrance and usually IRBs are fine with that approach. Elizabeth Buchanan, Ph.D. Endowed Chair Director, Center for Applied Ethics University of Wisconsin-Stout PO Box 790 Menomonie, Wisconsin, USA buchanane@uwstout.edu Principal Investigator, Internet Research Ethics Commons internetresearchethics.org (NSF Project # 0924604) elizabeth@internetresearchethics.org