Meetup.com is just fine. However, when I’m looking for events and activities, and I want some kind of quality assurance, that’s when I use my meetin.org account.

Every meetin.org chapter has administrators who aren’t afraid to reject an event/activity if it doesn’t fall within the guidelines. Besides, meetin.org is more fun! I can host any kind of event such as pizza parties, paintball, etc., without having to start a specific group.

Since you’re in California, I’d also recommend mixermixer dot com which is similar to meetin.

As for this meetup group, I (being a potentially rational dude) think,

a) This is probably a hoax.
b) If not, I don’t see how this activity is fun and I don’t know why people would do it … probably a bunch of losers/retards/illiterates etc.
c) Or maybe, there is a possibility that this activity has some element of fun in it that my limited mind can’t perceive. If I were to set out to explore the missing fun element(s), then I’d want to be really really careful (hey, you may never know what that blood stain on your shirt’s collar might contain). Besides, hey, there are plenty of other interesting things one could ponder about rather than invest time investigating this group.

But, is your concern that there might be some irresponsible gullible individuals out there who’d think that this is a “cool” activity to indulge in? Are you worried that such people might be in harm’s way? It seems like its a tiny group of 3 people. At the moment, with very little I know about this group, it doesn’t look like it might be a major social hazard but I’d be wrong.