The English language is changing. Always has been and always will. Since the birth of the interwebs, new words have been springing up like dragons sown from, erm, dragons’ teeth.
But here’s a change that involves way more than online communication, and it’s driving trad English teachers Ka-razy:

Call Them What They Wants
by John McWhorter
Yes, practice—I am trying my best to master this new way of using they despite the fact that, make no mistake, it’s hard. In contrast to the deliberateness of writing, speaking casually is a largely subconscious, not to mention very rapid, act. In addition, pronouns, like conjunctions and suffixes, are a very deeply seated feature of language, generated from way down deep in our minds, linked to something as fundamental to human conception as selfhood in relation to the other and others. I’ve been using they in one way since the late 1960s, and was hardly expecting to have to learn a new way of using it decades later. I thought I had English pretty much under my belt.
Some might find this an odd orientation from a linguist. After all, aren’t we libertine, permissive sorts, wedded to the unheedful idea that people should be able to just let it all hang out linguistically? If so, I might be expected to harrumph that people should not be asked to use language in ways that they find unnatural.
Quite a few of us, in fact, harbor a distinctly unnatural resistance to a related usage of they, which was until recently the one for which it usually made news. Tell each student they can hand in their paper at the front office. We are told that this sentence is incorrect because they can only refer to the plural. The proper user of English is to either use he to refer to both genders, to toggle self-consciously between he and she, or, in writing, to use little (and unpronounceable) monstrosities like he/she….