Whoever posting obscene posts, their profile are hacked. They even are not aware of those posts. Fundamental security tips to secure profile from being hacked: 1. In mozilla firefox, use private browsing. This option is available at the top menu bars. For google chrome, use incognito window. Right click at the top status bar, then select it. 2. Don't select 'remember my password'. 3. Don't choose to 'stay signed in'. 4. If u don't apply point 1, then just clear your history frequently or install c-cleaner. 5. Never click on advirtisement. 6. Don't left-click on download link, it's always safe to right-click on link and then choose 'save target as'. 7. Frequently change your password and use strong one.