Player alias is a tool created by echo which logs all Minecraft accounts found in a screenshare - taken from the player usernames file in .minecraft as seen here:

Player Alias isn't something to live by when it comes to ban evasion as the linked accounts could be from scans that are very old.

Firstly you need to search for all known Alias’ through your in-game /alts or /ipcheck commands:

For this example, I’ll user Lewisina (Me)

Go to the Echo.ac User Area and find the Player Alias Section

Once you find it type in the IGN of the player you are screen sharing and any accounts connected to their IP.

It will look like this:

You can double-check this through their “usernamecache” or “usercache” files in their .minecraft:

Go to: C:\Users\Lewis\AppData\Roaming\.minecraft

Double click the text files and look for the Usernames of the players. If they are connected to a banned account you can ban them!