Require all groups to be private so people's meetup responses, RSVP's etc are not posted automatically in google searches.
This makes it way too easy for someone to google your name and then find you all over public meetup groups. I love meetup and would hate to ever have to cancel my membership due to stalker issues. By requiring all meetup groups to be private, people would still be able to RSVP, see exactly who is going, etc but the general public who is not a part of that meetup, will not be able to find it all over google. I just googled my name and my comments, welcomes, and RSVPs are one after another. Scary!