Nothing is secure on internet not even the Govt. websites. You can try everything possible but that's not enough.
Both are secure but you have to applied security to your account in the setting. But i prefer facebook because in this we have lots of application as compared to orkut.
Facebook is much more secure. Read the wiki article on Orkut, it used to spread some worms and stuff to people who aren't careful about what they are clicking. Also, Orkut is much less useful to webmasters because it is hardly being used outside Brazil and India.Â
Facebook is more secure than Orkut. When Orkut is new at that time there is a craze of it but now most of the people in the world are using only Facebook.
I have both accounts but i am not using orkut or google plus 'coz they have not sufficient security I feel as a girl first of all I need Privacy. So facebook is too much securer then Orkut.