Edit: "Ye focht fae Wallace, will ye nae fecht fae freedom?"

@Brus. Aye, mon. Dinnae fash yersel aboot OED an' Websters. There's nae need to dree one's weird here. Ye fought for Wallace, will ye nae fight for freedom now?

"Tell" in the beginning meant to count as in "untold millions".
"Tell" has also been used in the sense of "recount" for hundreds of years.
In German the same word "zaehlen" = count, and "erzaehlen" = recount.
I think in German one can use "tell about" wihout a direct object; but maybe I'm wrong.
Maybe people using "tell about" in English have picked it up from German-speakers or are themselves translating from German word-for-word.
See here:

http://www.linguee.de/deutsch-englisch/uebersetzung/erz%E4hlen+%FCber.html

and note the Englisch in the fourth paragraph.

What is wrong with new words, new expressions? What is wrong with lifting a phrase from one arena and applying it to another? Are we so fumble-witted that we cannot take in new coinage - fumble-fingered under the high ball? Or are we so chained and bound by common usage, word-books, and by whatever out-dated ideas we were taught at skool?

I own up to being lorded-over by the spell-checker, just putting in hyphens to stop it red-lining, so what?

NB "influence" is widely-used as a verb despite its noun-ending; should we then use 'sway' instead?

@WW re Ngram: I agree KJV is there, so are 'arvo', 'whilom', 'highte' spkiking before 1600 so i guess Chaucer and Shakespeare are in there too. Ngram will not go back before 1500. Looking at "thole" vs "tolerate", it may be data before 1600 is limited; there just weren't many books.
Oddly "drone + strike" would peaks around 1600.
To be clear, I don't use google directly - i go thru startpage.com ; no mobile phone, so no drone-strike either!

Re common usage: this applies in particular to the google ngram viewer: just where does the bible fit in? Does it count just once? Does the KJV count at all? Yet surely one of the most widely read and influential set of words and collocations in the English-speaking world.

The other thing I am not sure about in speaking of common usage is this: looking at, say, Tolkien and his works which of course inhold many archaic words and usages) - the question is how do they affect 'common usage' - is it based on counting each book as one text or do we multiply up by the number of copies in circulation? Just how do these statistics work?
It would seem unfair to lend equal weight to a widely-read work and some book that just ran to 500 copies all unsold.

Re common usage as a criterion:
in teaching English to speakers of other languages (ESOL) common usage is rightly the main criterion: one wishes to teach "normal" English. To some extent this means one is teaching cliches, and set word-strings, and marks "global warming" as "right" and "worldwide warming" as wrong, simply on the basis of common usage, assuming that the student is unaware of the norm.
Teachng English to native speakers may be different, almost the opposite. One might assume that they already know the norm, and be looking for more creative use of language; so "worldwide warming" might indeed gain extra marks in the right context.
Part of producing creative writing is (in my opinion) coming up with a freshness of collocation, breaking the norm for impact, and to make it memorable.
The other weakness of making common usage our sole benchmark is that it would go against both the creation of new words/meanings/phrases and the use of lesser-known or dialect or dated words, and against the freedom to simply say what we wish in our own way. Of course there are limits, or one would not be understood, or the reader/listener finds it all too overburdening. There is a time and place for creative writing (and a time and place for "creative" accounting too). "Just google it!" is a good example. Just when did this become "common usage" ? In 2002 I would have marked this as "wrong"; just as today I would mark "Just firefox it!" as wrong.
But really why not? I never use Google itself.

"Thus, the heroes of today are no longer individuals living but anonymous dead."

@WW No, but I've gotten used to AmE spellings since reading economics and accounting using Am textbooks and working for multinationals where "labor costs" was the norm. I can still get out "Wotcha guv" to the bloke from London at the local garage, though.; but it don't come easy after decades abroad. Fluctuat nec mergitur.
As for what I teach, well I don't mark the following as wrong:
"Did you do your homework yet?" as so many have had Am teachers before.
I think in CPE the requirement to use EITHER AmE OR BrE (grammar and vocab) has been withdrawn.