Can I completely remove the online friends box in lower righthand corner?

It always in my way even when I collapse it. very irritating.

Well I just realized you can collapse it even further if you move again after the initial collapse which puts it out of the way but still I'd rather not have to deal with it everytime I come here.

You can hide this box with your own userstyles, e.g. using Stylus.

Chrome: chrome.google.com/webstore/detail/stylus/clngdbkpkpeebahjckkjfobafhncgmne
Firefox: addons.mozilla.org/en-US/firefox/addon/styl-us/

And add these styles:

@-moz-document domain("lichess.org") {
#friend_box { display: none; }
}