By default, if your event page is public, the attendee nicknames and number of attendees are publicly visible on your event page.
Number of attendees shown on event page.
Click More attendees to view the event attendees (nicknames).
How to edit the attendees display settings
You can customize the attendees display by selecting "Show attendee nicknames" or "Show number of attendees" at anytime. If you wish to hide the attendees display, you can uncheck the items on the Edit Event page.
To edit the attendee display settings, please go to Edit Event page.
Locate Attendee Display on Event Page and customize the display by selecting or deselecting the items. Then, click Save.