If you are using your own laptop at different locations you are wasting your time. These can easily be tracked in todays world. The whole idea of using a different isp or switching your network or physical ip address no longer will protect you.
http://www.zdnet.com.au/news/security/soa/Tracking-PCs-anywhere-on-the-Net/0,130061744,139183346,00.htm the article came out in 2005, much has advanced since then. So unless you use your laptop ONLY in locations that are not your house or you use someone else's computer, say at a internet cafe type place you can be just as easily tracked as if you post at your house.
Posting on someone else's computer poses a whole different set of risks, especially at a commercial business which may track websites you go to while you are on their computers as well as upload/downloads (it is their computers, they don't them used for illegal activities or for someone to try and get unlimited access to their computers).
If you do connect your laptop to the internet only from places not your house, they can still get a general idea where you are at. I'm not sure how this may help them though.
When it comes to using programs to try and protect yourself, those are only good for stopping normal hacker/crackers. The government has access to some of the brightest computer/security minds with vast amounts of money. To say the least, their technology and abilities are far superior to ours.
The cyber attacks on the department of defense, thought to have been propagated by the Chinese government, has not helped this situation. The U.S. is increasing the budget for cyber warfare by substantial amounts to try and combat the threat the internet poses. This is thought to become a large part of war in the future.
Trust me, if they want to find you, they will. Posting online no matter how you do it is a risk. You can minimize your risk by controlling what you say and if/how you post pictures. It all comes down to whether the government really cares to put resources to find you, which I believe is no. But who knows how easy it is at this moment to find you or in the near future. It may get to the point where it takes little effort to track someone and regular police/dea agencies will be able to do it. At that point, who knows whether they will want you.
