A study from DNS-resolution service OpenDNS, 2010 Report on Web Content Filtering and Phishing details the sites companies were most likely to be blocked last year, be it social networking websites or sites that have a reputation for fostering procrastination.

OpenDNS, a pioneer and leader in the Security as a Service space is also the leading provider of DNS-based security, infrastructure services, web content filtering and malware, botnet and phising protection.

Below is the list of 10 website, which are among the most blocked by companies.

1.       Facebook 23%

2.       My Space 13%

3.       Youtube 11.9%

4.       Ad.doubleclick.net 5.7%

5.       Twitter.com 4.2%

6.       Hotmail.com 2.1%

7.       Orkut 2.1%

8.       Ad.yieldmanger.com 1.8%

9.       Meebo.com 1.6%

10.   eBay.com  1.6%

Top Ten Blocked Categories

Not surprisingly, the top ten most blocked categories are focused on providing a safer Internet experience for students and children, and a more work-appropriate environment for businesses. Percentages indicate the proportion of networks using category blocking that reference a given category.

1.       Pornography - 85%1

2.       Sexuality - 80.1%2.

3.       Tasteless - 77.3%3.

4.       Proxy/Anonymizer* - 76.2%4.

5.       Adware - 69%5.

6.       Nudity - 67.2%6.

7.       Hate/Discrimination - 58.7%7.

8.       Lingerie/Bikini - 58.5%8.

9.       Gambling - 58%9.

10.   Drugs - 57.3%