Especially in large multiplayer sessions, you may want to hide others' avatars to focus. Here's some code to do that:
1var ss = document.createElement("style")
2ss.type = "text/css"
3ss.innerText = ".user-label { display: none }"
4document.head.appendChild(ss)
To show the avatars again, remove that node:
1ss.parentNode.removeChild(ss)