As much of the technology world recoiled last week at the latest evidence that Google is reaching into users’ personal lives for more details it can sell, one small group of companies were celebrating. After all, here was an enormous growth opportunity for a fledgling market in services that protect people’s privacy online."Ultimately, when we talk about privacy online, we’re talking about invisible data," said Brian Kennish, co-founder of Disconnect, a year-old startup that creates software that prevents sites from collecting data about its visitors.