You can both mute and un-mute all users—or outright ban disruptive ones.
To mute the entire audience, you can click on the Mute All or Mute newcomers button on the bottom left-hand side of your screen. Audience members can unmute themselves.
If participants forget to unmute themselves while speaking, the speaker can ask them to unmute by using the Ask user to unmute button.
To mute one participant, click on the ... next to his/her name, a dropdown menu will appear, click the Mute option.
To ban a participant, click on the ... next to his/her name, a dropdown menu will appear, click the Ban participant option. A new box will come up to choose how long you would like to ban the audience member. Click Ban participant.
Quick Tip: available bulk actions for speakers in the Participants panel include muting all audience members simultaneously.