You can, however, choose to be hidden from friends, ensuring at least some level of privacy.
All you have to do is show up — no messaging required.
Unlike most other apps that have you log in through Facebook, Beacon has you log in with your Twitter account.
You can create "events" — see if others want to meet up for a drink or pool for a Lyft — and then either limit the invite to mutual Twitter followers or make it public.
The app shows you others who are also interested in going out.
Select people you'd like to meet and Tonight sets things up for you, even going so far as to pick a cool spot to meet. The sole downside is that the app is currently only live in Manhattan and Brooklyn.