The message is a bit vague, but we chose that wording because it conveys the point more succinctly than a complete explanation.
If someone forwards an email to a friend, that friend will be able to RSVP and comment on behalf of the forwarding user, but they won't be able to create/edit/cancel the event. All of the admin controls still require the admin to login.
We chose this as a matter of convenience since most people will refuse to RSVP anyway and if we required them to fill out a registration form first, we wouldn't be any better than evite. As noodle mentioned, if someone can RSVP on your behalf for a single event, it probably isn't the end of the world. It's completely depending on the security requirements of your app.
If someone forwards an email to a friend, that friend will be able to RSVP and comment on behalf of the forwarding user, but they won't be able to create/edit/cancel the event. All of the admin controls still require the admin to login.
We chose this as a matter of convenience since most people will refuse to RSVP anyway and if we required them to fill out a registration form first, we wouldn't be any better than evite. As noodle mentioned, if someone can RSVP on your behalf for a single event, it probably isn't the end of the world. It's completely depending on the security requirements of your app.