>>15010404
[@]
[SCARE]
pretty sure the reference was twitter/online
-note that the first instance of this symbol is found in a Bulgarian translation of a Greek chronicle written by Constantinos Manasses in 1345. it features the @ symbol in place of the capital letter alpha "Α" in the word Amen. Why it was used in this context is still unknown. The evolution of the symbol as used today is not recorded.
most common use prior to the common usage would seem to be trade/commerce
and a picture of the earliest know typewriter with the symbol. (1889)
https://web.archive.org/web/20141225121941/http://www.shadycharacters.co.uk/2011/08/the-symbol-part-2-of-2/
https://en.wikipedia.org/wiki/At_sign