You can control to whom your profile shows up and how many meetings of which types you're available for.
- Click on your profile image in the upper right and then select "Preferences" from the drop-down
- Select "Privacy" from the menu on the left - here, you can decide how visible you'd like to make your profile
- Select "Availability" from the menu on the left - here, you can turn your availability on / off and, if you turn your availability on, specify how many meetings per month you'd like to be available for.
Note that, depending on your user type, your account may already be hidden! If you don't see the Availability and Privacy sections in Preferences, then your account is already invisible to other users.
More detailed instructions for adjusting account privacy and availability can be found here.