OpenDNS, one of the most popular DNS services on the Internet, is frequently used by parents and organizations to block websites that they think are inappropriate for children or may hamper productivity at the workplace.

OpenDNS, which claims to handle DNS requests for 1% of Internet users worldwide, has released a report detailing a list of top 10 websites that are most frequently blocked by home users and business users.

The list includes social sites (Facebook, MySpace, Twitter) and adult websites (Redtube, Pornhub and Playboy) as usual but the presence of two major advertising networks on that list suggests people do have their share of privacy concerns.

Here’s the complete list of frequently blocked sites from OpenDNS. Percentages indicate the proportion of OpenDNS networks using blacklisting that reference a given site.

1. Facebook.com — 14.2% 2. MySpace.com — 9.9% 3. YouTube.com — 8.1% 4. Doubleclick.net — 6.4% 5. Twitter.com — 2.3% 6. Ad.yieldmanager.com — 1.9% 7. Redtube.com — 1.4% 8. Limewire.com — 1.3% 9. Pornhub.com — 1.2% 10.Playboy.com — 1.2%

Top Websites Blocked in Offices

When it comes to organizations, a surprise element in that list is Meebo – it’s a web app that lets you chat on Google Talk, Facebook, etc. simply using the browser and a popular workaround when you cannot install the regular chat clients on your desktop.

The fact that Orkut made it to the list seems to indicate that OpenDNS has a strong user base in India. You can read the full report below or download it from OpenDNS.com.