From the IT Core Services - Service Desk:

Zoom has started to proactively contact UCSB end-users and Zoom account administrators when they share Zoom Meetings created without a Passcode or Waiting Room on social media (Twitter, Facebook, etc.). 

If an end-user creates a public meeting (if they don’t enable a Passcode, Waiting Room, or meeting registration) and advertises that meeting on a social media channel, it’s an easy target for Zoombombing. Zoombombers seek links to public meetings on social media in which to cause problems. 

Although adding a Passcode will meet Zoom’s criteria for not reporting the event, we strongly recommend that any meeting that users plan to advertise on social media enable the Waiting Room to discourage Zoombombing. Adding only a Passcode will still give Zoombombers access to your meetings if the Passcode and meeting link are advertised together. 

If users need events to remain public for logistical reasons, they should convert them to webinars, which have more host control over the event, and less possibility for Zoombombing. 

If you need assistance obtaining Zoom Webinar functionality, please submit a ticket.