Even if you delete normal tracking cookies regularly to evade tracking by snooping sites and eager advertisers, little-known Flash cookies may be making an end run around your attempts to preserve your privacy.

Flash cookies (also known as local shared objects or LSOs) can save certain Adobe Flash-related settings--storing preferences for watching Flash video on a certain site, for example, or caching a music file for better playback.

"We won't share your information with third parties." You've no doubt seen that common phrase in Web site privacy policies many times. You might think that the site in question won't divulge details about your visit to other companies or organizations. But according to a study by privacy researchers at the University of California, Berkeley, sites have a huge amount of wiggle room with that promise.

The in-depth study dug into the privacy policies and tracking practices of the 50 most visited Web sites as listed by Quantcast. The researchers discovered that loopholes such as affiliate sharing and tracking code allowed for much more data sharing than you might expect.

Given the slew of embarrassing stories you've no doubt seen about users accidentally sharing too-personal information, the idea of preserving privacy on a social network may seem like going outside during a thunderstorm and expecting to stay dry.

But at the same time, sites such as Facebook are developing into major hubs for seeing new photos of the latest baby in the family and keeping in touch with far-flung friends and relatives. For example, when my brother recently suffered a major injury, the family got updates on his status via Facebook. So if you'd like to try to stay dry in that online social storm, here are some rules of thumb for using the site without letting the entire world know your business.

Cell phone apps like Loopt and the new Google Latitude allow you to track your friends' physical locations, and be tracked in return. That can be a huge boon for meeting up on a Friday night-and a real nightmare for privacy if proper safeguards aren't in place. (Read more on cell phone privacy.)

I checked out both applications. For starters, neither will share your location with anyone until you explicitly agree to such sharing with each individual friend. So you can install either one and see how it looks without divulging where you are.

On January 20, as most of the nation focused on an historic inauguration, Heartland Payment Systems, a credit card payment processing company, acknowledged that data thieves had installed spyware on its network to steal credit card details throughout 2008. The company says it handles about 100 million payments a month, and doesn't yet know how much information was stolen; the theft might be the biggest data breach ever.

But does anyone really care? Or rather, should anyone care?

Why do we need overarching privacy and security rules governing how companies deal with our most sensitive data? Well, let's consider the case of the ongoing million-dollar manhunt for extortionists who have threatened to display millions of stolen health records--complete with prescription information--online.

The continuing investigation, backed by an offer of a $1 million dollar reward for information leading to the arrest and conviction of the crooks, stems from an event made public in November. Express Scripts, a large company that manages prescription-drug benefits, reported that both it and its clients had received letters threatening to reveal customer information--including Social Security numbers, addresses, dates of birth, and prescription information--if certain extortion demands were not met (for more information, visit the Express Scripts Support Site).

If you're among the multitude of people who rely on the Firefox browser to remember their Web site passwords (and there's no denying that I am), here's something you might like. The latest version of the popular, free Foxmarks add-on now has a feature for synchronizing and effectively backing up the passwords that your browser stores, in much the same way as it does for your bookmarks.

It's dead simple to set up Foxmarks so that whenever you add a bookmark to your browser at work, the new addition will also be automatically synced to your browser at home, and vice versa. For example, if you install Firefox on a new PC, you can install the add-on and give it your Foxmarks account information; and all of your usual bookmarks will be available almost immediately. You can also log into my.foxmarks.com to view and organize your saved bookmarks.

Far more dangerous than a normal e-mail attack, targeted at­­tacks choose a particular person as the prospective victim and tailor their message to that recipient. Since their creators craft the messages carefully (with few spelling and grammatical errors, for example), these attacks lack tell-tale indicators and thus stand a far greater chance of snaring a victim.

A recent e-mail blast sent out to LinkedIn users followed this pattern. The e-mail, which appears to have come from support@linkedin.com and addresses LinkedIn members by name, purports to provide a requested list of exported business contacts. In reality, the attachment launches a malware assault against anyone who double-clicks it.

All the major browsers--Firefox, Internet Explorer 8, Safari, and even the new Google Chrome--now have or will soon have a major privacy feature. The name varies from browser to browser, but the basic intent is largely the same: While active, it masks your browsing trail from anyone who might later sit down at that PC and try to check the browser's history, cookies, and other data.

While these features should prove effective in that situation, they won't disguise you from the sites you visit; sites will still be able to record your IP address and monitor the searches and other information you enter. And more important, the technology won't make you any more or less safe from Web-based attacks that might surreptitiously attempt to infect your PC with malware when you view a page--the favored approach among money-minded digital crooks these days. So you'll still need to be careful where you surf.

Comcast's move to limit its broadband customers' throughput to 250GB per month starting in October might anger those who want unlimited access, but it's actually good for privacy. Because the cap applies to all traffic equally, it doesn't require that Comcast snoop for particular types of application data. Contrast that with its previous (and initially undisclosed) practice of interfering with peer-to-peer traffic (in an effort to limit customers' downloading of huge, bandwidth-hogging files). The ISP says less than 1 percent of customers will be affected.

Of course, there's nothing to stop broadband companies from snooping in other ways. AT&T, for example, said earlier this year that it's investigating ways to dig deep into its customers' Internet traffic in search of copyrighted material, according to the New York Times. Meanwhile, AT&T is still getting flack because of its alleged spying on Internet traffic for the National Security Administration, without warrants.

To help you determine whether a particular alert is worthy of Chicken Little or is truly dangerous, here are translations for some of the most common threat terms.

A recent BusinessWeek article detailed a number of examples where the data gathered by information brokers conducting background checks on prospective or current employees was incorrect, or at least disputed, and cost people jobs. Thankfully, you can examine some of your records ahead of time, as you can (and should) do with your credit report, to make sure no surprises pop up when someone checks them.