It’s a tough time to be a trusted brand. Information (truth and hearsay alike) flows like water, opinions spread like wildfire—one day your brand is synonymous with trust for millions of people, the next it’s being dragged through the digital mud by a few over a product recall or privacy violation. And it’s all happening faster with bigger implications and greater transparency than ever before.

Brands no longer get to rest on their laurels. We’ve stopped basing our trust of successful brands on the mere knowledge that they are financially successful—or because they run ads that tell us we should trust them. In fact, it seems the very definition of “brand trust” is morphing in front of our eyes. More often, an increasingly-skeptical public is flocking to the web for real-time information and social network commentary posted by “officials” or by anyone else with an Internet connection and an axe to grind.

So, this begs the question: how should we begin to redefine and measure brand trust? Essentially, trust is still a currency that brands earn, lose… and even occasionally regain. Trust used to be measured one voice at a time in the aisles of supermarkets and in the offices of doctors. But how can its value accurately be measured now that millions of voices are screaming their opinions about everything, all the time? How can you differentiate public opinion when violations as minor as misspellings are condemned in public forums with equal fervor as high-level corporate gaffes?

Curiously, the answer appears to be different for different types of companies. People are holding older, established companies and newer born-digital companies to widely-varying standards and expectations. To illustrate, here’s a hypothetical scenario: FedEx announces that, starting this week, they will begin opening all of your packages to see what you’re shipping, and then storing that information and analyzing it for trends—they promise they won’t harm any contents and will re-seal the packages perfectly. Then they announce that they will be improving your life by selling their findings to advertisers who can then deliver more relevant, better-targeted product ads directly to your doorstep without you having to make any additional effort. Do you continue to trust this company and recommend them to others? No?

Yet, here we have Google – whose motto is “Don’t be evil” – openly admitting to having developed fancy algorithms that anonymously read every piece of your Gmail and serve you targeted ads based on their content. Like established banks and credit card companies have always done, they make no secret that they’re collecting information, but this goes well beyond purchasing habits to include everything you search, read, visit, send, view, and produce through their sites – in the “privacy” of your own home. And yet the level of public trust in Google seems to remain very high.

Why is it that born-digital brands seem to benefit from a double-standard on trust versus established – or even transitioning-to-digital – businesses? Perhaps it’s because we’re sending our hard-earned money to the established ones. When we’re shelling out for goods and  services, we expect a higher level of protection in return. Google, Twitter, Facebook? We never have to send them a dime, but instead freely send them our most personal information – our thoughts, our photos, videos, likes and dislikes, purchasing habits – and only peripherally consider what they do with that information because their services are just so great. But, when they sell our personal information or share our intimate details with anyone who comes asking… what did we expect we would get for free?

Perhaps it’s time to ask whether trust even has any effect on purchase and usage patterns any more. Last week Facebook’s Mark Zuckerberg declared open war on privacy. The result: an uproar, to be sure, including open letters from senators decrying the policy, and a request to have the site investigated by the Federal Trade Commission. But Facebook’s active user count (currently over 400 million) doesn’t seem to be taking any dives. And before that incident, Google was caught sniffing and storing personal data from Wi-Fi networks through its Street View vehicles. Again, no sign of rats fleeing the good ship Google—perhaps with the exception of the German government.

It must be tempting for companies making their first forays into social networking to simply plug Facebook Connect in to their sites and build a large public audience, but when they do, they may have just inherited all the negative associations people have with Facebook’s privacy policies. It’s a volatile world and your brand – whether established or just becoming established – may find itself at the mercy of a fanatical minority empowered to be 24/7 critics, and in an atmosphere where trust can be as fleeting as a single Tweet.