Free speech is something that needs to be protected, however, it's a two way street and is not just for the popular or PC view. If you replace the "white" in Ms. Khan's hashtag with any other race or religion, it would be consider racist! If you don't agree, then try it and see what kind of reaction you get! I dare you! I'm sorry, but unfortunately white people are not the only ones who are racist. 
"I refuse to accept the view that mankind is so tragically bound to the starless midnight of racism and war that the bright daybreak of peace and brotherhood can never become a reality... I believe that unarmed truth and unconditional love will have the final word."
Martin Luther King Jr. 
Have a great day everyone!