CAPTCHAs, where humans distill words from squiggles, hold line in spam war
(Newser) -
Every web user has come across CAPTCHAs: wavy-lettered depiction of words you must retype as text. Most pay them no mind, but, Lev Grossman writes in Time, we should reflect upon completing one. They're one of the rare visible skirmishes in the largely invisible war between spammers and security programmers....