One star is too many. Can we give it no stars here?
I'm the owner of a Meetup website (group). This is a PAYED service, but the customer service is the worst I've ever seen or heard of -- which is to say they never actually communicated with me by email when I reported a problem. And they apparently are not accessible by telephone at all (I could not find a customer service phone number for them on their website).
What is more, Meetup apparently prevents users of its messaging service from voluntarily sharing their email address with others in the group via their messaging service! I've had several people respond to my request for their email address by sending that address... which Meetup blocked! In the place of the email address these people sent was five asterisks: *****.
Meetup needs to be replaced by a superior service which offers the same kind of service, only better. Perhaps Meetup themselves will realize this and repair their egregious errors of judgement.