I hadn't heard of the brain damage link. When searching for information on it, however, I mainly came across references to a study last year that said it is does not, in fact, cause brain damage. Additional mystery ingredients might be another story.

http://www.guardian.co.uk/society/2011/feb/19/ecstasy-harm-b...

http://www.addictionjournal.org/viewpressrelease.asp?pr=147