Hide participants from each other
It is possible to hide participants from each other. This way, only the organizer sees the participants in the event. You can do this in the ‘Who?' step on the page 'Who do you want to invite?':
Have you already created the event and want to change this setting? Open the event and click ‘options' in the 'Who?' section. Then choose the option ‘edit participants'. Then, you can change the option and update the event. Note: existing participants are not invited again, so don't delete them unless you really want to!