Fewer is Better
Over time, if you are not careful, you might end up granting posting authority to more DApps than necessary.
Whenever you log into a DApp that interacts with the Hive blockchain, often you will need to give that application posting authority to perform certain actions on your behalf. It is important to trust that the developers of said application won't misuse this authority. The long and short of it is, you should monitor your granted authorities and remove those that are untrusted and/or not being used.
What a mess! I don't use most of these. Many of them I haven't used in years. Okay, while I am cleaning up my own junk, let me walk you through the process using Peakd.com. I will make this short and concise.
Log into peakd.com using your preferred method (Hive Keychain FTW!)
Navigate to your permissions page: @your_username/permissions
Click the AUTHORITIES tab
Click the X next to an app you are no longer using and select 'Confirm'
Repeat process until you are left with only the apps that you currently use.
That's All There Is To It
It is worth checking your granted posting authorities from time to time and keeping them pared down. I just realized that I had quite a mess myself, and thought that others could benefit from knowing how to clean it up. There are a lot of moving parts to Hive and it's easy to get lost and confused. As the world's most disorganized person, I know this all too well!