There’s a lot of controversy over whether and how the internet should be policed. Look at bills like SOPA and PIPA in the US, or the censoring of the internet in China. But the internet can be a resource for the police as well.
This Mashable article goes through just some of the crimes thanks to facebook. And another Mashable article has highlighted a recent ruling in the US Court of Appeals which will let police search through mobile phones found at the scene of a crime.
The internet has changed the game for policing. On an international level it becomes confusing what the laws even are and who they apply to.
For internet users the line of privacy is wiggly, since it can sometimes be confusing to control.