Facebook
Facebook's list of 40 most shared articles of 2011 is quite revealing. Among the stories most shared -- Ryan Dunn Dead: 'Jackass' Star Dies In Car Crash, by The Huffington Post. REUTERS

The Silicon Valley of India witnessed the biggest hacking Tuesday when many Facebook users from Bangalore city realized that their accounts have been hacked. To add more embarrassment a link was posted on their wall directing to a graphic image where their faces were morphed on a naked body.

Facebook started receiving reports of pornographic and violent images being put on their walls on Monday, and with time the wave of reports started swelling. Users reported about links, images and videos being posted which showed doctored photographs of people in compromising situation, violence, self-mutilation and bestiality.

Some links also showed the popular teenage singer Justin Bieber in compromising situation.

Facebook received over 6 million complaints regarding pornography and violent content.

We have recently experienced an increase in reports and we are investigating and addressing the issue, Facebook spokesman Andrew Noyes told FoxNews.com. We are always working to improve our systems to isolate and remove material that violates our terms. Protecting the people who use Facebook from spam and malicious content is a top priority for us.

Many users went to Twitter and MySpace to share their most horrible experience with Facebook, and many of them are thinking of permanently deleting their profile.

Here are some steps to keep your Facebook account safe if you are not deleting your Facebook profile.

1: Change your password if you see any suspicious changes in your profile. Changing password makes sure that no one can access your account if in case your login details were saved in any computer you used earlier.

2: Remove unwanted and suspicious applications in order to not allow them access to the contents, details and contacts available in your account.

3: Run a thorough virus scan so any Trojan Horse kind of virus which accesses data from your computer, including passwords, will be recognized and removed before they damage your public profile.

4: Change your privacy setting and allow only the people you know to access your content like friends list, photos, videos and info.

5: Change your settings to allow friends only to write and post on your wall.

6: Don't add people you don't know. Even if you add them make sure the person is trustworthy and genuine.