See what channels someone is following.
Twitch allows any user to see who someone is following, using their official API. Twitch Database just adds a nicer interface.
It's impossible for you to hide who you're following. Any user will always be able to see to you're following through Twitch's official API. However, if you'd still like to be unsearchable, you can click "Dashboard" top right and there you'll be able to opt out.
This can take a while if they are following a lot of channels.