What is skiplagging, the money-saving travel hack that airlines loathe?

A company that sells the ability to identify a stranger from a photograph left more than nine million files unsecured online, a researcher found. ClarityCheck sells reverse image searches. A user uploads a photo and the site returns names, social profiles and where else the image appears online. Canadian visitors are quoted $1.69 for a seven-day trial and $38.99 every 28 days after that. The company also sells lookups on phone numbers, email addresses, vehicle identification numbers, names and businesses. Its homepage says it can “identify unknown callers, verify online contacts,...