Handle weird input in node.js and/or angular.js

I have a <textarea> where users input text. Sometimes they copy text from excel and get a "group section" character in the mix which causes problems.

screenshot from sublime

How would you usually handle this sort of problems to filter away unwanted characters?

I'm specifically looking for answers for angular.js (which the front-end is done in) and node.js (which the RESTful back-end is done in).