One thing you always need to look out for - number one. That, my friend, is YOU! You have to monitor your online presence and keep watch for any undesirable material that may crop up. It is NOT impossible to defend yourself against anti-YOU content! And although it can be quite difficult to fix a damaged online reputation -- it's NOT impossible.
The permanence of the web is persistent and for anyone seeking to destroy or disable information, it presnts a huge challenge: once negative content is out there in the digiverse, it's dreadfully hard to delete. If you yourself are responsible for the creation and deployment of the objectional and/or questionable content (an errant tweet, a stupid YouTube video, a naked or drunken photograph on facebook) you can delete it and -- eventually -- it will be eradicated from the caches of Google and other search engines (you can hasten the process by asking Google to remove a page or site from its listings -- but only once it's been taken down). If you don't control the content, all you can really do is ask the person who does to remove it.
if you have the time and patience to methodically follow the proper procedures, you have a great shot at rehabbing your reputation online. If you find that you can't do it yourself, therer are some amazingly good services available, such as reputationdefender, which will handle the "cleansing process" on your behalf! Remember, in the end its your reputation and your responsibility.
The popularity of social networking sites continues to increase, especially among teenagers and young adults. The nature of these sites introduces security risks, so you should take certain precautions.
The best way to keep unflattering information about yourself out of Google is to keep it off the Net. That means tightening up privacy at all your online hangouts: Facebook, Twitter, Linkedin, etc. Be careful when you comment on other blogs and watch what you say in web forums, which are also indexed by Google unless the administrator has added a "do not index" tag to his forum. It goes without saying (but I'll say it anyway) Be careful what you post on your own Web site or blog.