The internet is a fun place, full of information and entertainment and of course, the good and bad people. The security online sites all talk about how to protect your identity and stop your profile being stolen or misused.
The advice is mostly right, but it does not cover the important aspect of sometimes it is vital to have an identity online that is not yours. Think about being a whistle-blower of an organisation and think about someone or some organisation that needs to tell the public about sensitive matters and ideas, and there is no way they can afford to have their original identity used.
In those cases, and in many others, it is understandable to have a fake profile that cannot be attributed to them. These fake profiles allow them to give information out that is in the public good and allows them to continue to do that over a period of time from within organisations.
Perhaps it is a little bit of the social Wikileaks aspect that is now fighting back against governments and large multinational organisations. These people take risks, not for money, but to get the truth out there.
These people need fake online profiles that cannot easily be routed by people that what to shut them up.
Many sites will tell you how to achieve false online profiles, but perhaps the best way is to read how not to have it happen and understand how it can be done.