To be fair, of course, rhyming road-safety signs are common along India's expressways, so Mr. Rushdie was himself borrowing on a theme. But like everything else, even this minute similarity — homage? remix? rip-off? — became part of the ceaseless compare-and-contrast debate.

Indeed, whatever Ms. Viswanathan's culpability (she maintained, by week's end, that all similarities to Ms. McCafferty's books were unintentional), one might hope the episode would be the final object lesson for would-be plagiarists who still think that their indiscretions can escape scrutiny.

In the age of the Internet, literary exegesis (whether driven by scandal or not) is no longer undertaken solely by pale critics or plodding lawyers speaking only to each other, but by a global hive, humming everywhere at once, and linked to the wiki. And if you are big enough to matter (as any writer would hope to be), one misstep, one mistake, can incite a horde of analysts, each with a global publishing medium in the living room and, it sometimes seems, limitless amounts of time.

Frontier justice? Mob rule? Perhaps.