Have you been phished? Whether you use a Mac, Windows, or Linux, iOS or Android, there's a real strong chance that somebody has sent you an e-mail or text message in an attempt to get at your personal information. Data means money, and you're a big ol' dollar sign to the bad guys.
The best recommendation I can offer is to browse smart. That means you ought to always double-check the URL of your banking site, social networking site, and e-mail site before you log in. Most browsers, including Firefox, Chrome, and Internet Explorer, now include a color-change on the left side of the location bar to indicate that the site has been verified as legitimate. It's always a good idea to type in the URL by hand, and to never follow links from an e-mail. Also, checking for HTTPS instead of the less-secure HTTP is a good idea, although HTTPS isn't foolproof.
But what about that link to some ostensibly hilarious video your best friend just posted to Twitter? There are several services you can use to verify a link. Google Safe Browsing is a good place to start. Type in this URL http://google.com/safebrowsing/diagnostic?site= followed by the site you want to check, such as google.com or an IP address. It will let you know if it has hosted malware in the past 90 days.
Another similar service is hpHosts. Enter a site into the search box and its database will tell you if the site has been used to distribute malware or phishing attacks. HpHosts gives you more-detailed information than Google Safe Browsing, if you're into that kind of thing. Two other excellent services are Norton Safe Web, from Symantec, and Unmasked Parasites. Pop in the URL, and you're good to go. Or if the site comes back as unsafe, don't go.
Many security suites come with browser add-ons to check links you click on the fly, and those work fairly well at scanning your search results and adding icons to indicate if a link is safe or not. If you don't have a suite, AVG LinkScanner (download for Windows | Mac)is a free add-on that works with both Windows and Mac, and AVG's free Mobilation Android app (download) or Lookout Mobile Security (download) will block malicious links on your Android device.
Sadly, iPhone and iPad users are out of luck. Even though phishing over social networking has been proven to work on iOS devices that haven't been jailbroken, Apple doesn't allow such link-checking apps. Feel free to recommend your favorite in the comments below.
UPDATED: The Google Safe Browsing instructions and URL have been fixed.