When fast user switching is enabled, all users are allowed to see other users' locally connected disks.

The Shared folder is set up to allow all users to read and write files, but only the user who owns an item can delete it from the Shared folder. This is accomplished using the sticky bit permissions setting.

The Ping tab of Network Utility allows you to test basic connectivity to another network host by sending and then waiting for the return of a ping packet.

You can prevent automatic updates for all users by disabling the options in App Store preferences. You can further restrict a user's ability to use the Mac App Store by configuring Parental Controls for the user's account.