My stalker found me through Meetup.com because of their lax Privacy Policies in which case they did nothing to ban her from the site. Organizers don't want to deal with the "drama" so they ignore any requests for bans. And, because anyone can start a group with no guidelines or expectations set in place by Meetup.com for Organizers, Organizers can chose to do whatever they want without reprocutions, such as ignoring pleas for help.
FYI: If your name is used for your account or if your name is listed in any comments in any group, you will come up in any online search of your name and every single group you are a member of will show up. This is a great way for stalkers, employers, or anyone else to find you!
Mine did this, and then proceeded to sign up for every group I was a part of, then proceeded to slander me in groups, and act like she was going to show up to an event - only to never show up, but only psych me out from attending anything fearing she'd be there.
Did Meetup do anything? Nope.