Please RSVP. If an event is full, it is likely due to the lack of space. Having too many people in a location also attracts unwanted attention and could lead to us being asked to leave the location, or not being allowed to return. It also makes it difficult to photograph around other photographers if there are too many people.
The Meetup.com Terms Of Service are specific about crashing without RSVPing. It's grounds for being removed from a group and/or the Meetup.com site entirely. If the location is "public", you can attend at any time. If you show up without an RSVP on the same day/time as the group, it will be considered crashing.
This includes bringing an unexpected guest that was not reflected on the RSVP, we love friends and family, but make sure they are reflected on your RSVP.
If you are not on the "Going" list, do not attend and please make sure all guests are listed on your RSVP.