How do I delete log files of websites I visit?

Question

When I connect to the internet, every site I visit is registered on the server in their log files with the IP and date.

How long do these log files stay on the server and how can I delete them?

Answer 1

This is totally dependent on who is running the server and the policies they have set up. It can range anywhere from not keeping any log data, to keeping your IP address, browser, referrer, and other data. They may keep this data for days, up to several years, but typically for 1 month on a typical Apache weekly log rotation schedule.

Only an administrator of the remote server can delete this. You, as an end user, have no control over this (besides where you point your web browser).

Answer 2

As pointed out, you have no control over how your IP address is retained by a website owner. However, what you do have control over is what IP is given to the website. Using various proxy tools, in particular Tor, you can anonymize your web browsing to (usually) pretty good effect.

It's not perfect, but it will conceal your origin from most commercial website owners. Government entities -- particularly those with access to law-enforcement taps -- are another story entirely.

Answer 3

Even worse: it's not only registered in logs of the server of the site you visit, but often also in databases of tracking services.

Google Analytics, for example, not only tracks your whereabouts, but also collects the contents of first-party cookies. That is: the cookies from the site you're visiting (so: not only Google's own cookies):

Analytics also sets and reads first-party cookies on your visitors' browsers in order to obtain visitor session and any ad campaign information from the page request. When all this information is collected, it is sent to the Analytics servers [..].

And the funny people at United Virtualities thought the following was a good use of Flash Local Shared Objects, to restore any normal HTTP cookies a user has deleted:

"All advertisers, websites and networks use cookies for targeted advertising, but cookies are under attack. According to current research they are being erased by 40% of users creating serious problems," says Mookie Tenembaum, founder of United Virtualities. "From simple frequency capping to the more sophisticated behavioral targeting, cookies are an essential part of any online ad campaign. PIE ["Persistent Identification Element"] will give publishers and third-party providers a persistent backup to cookies effectively rendering them unassailable", adds Tenembaum.

But, all just to help you, of course:

To justify this tracking mechanism, UV's Tenembaum said, "The user is not proficient enough in technology to know if the cookie is good or bad, or how it works."

But well, your government might be tracking more than you like as well, like The Electronic Police State, 2008 National Rankings:

1. China, 2. North Korea, 3. Belarus, 4. Russia, 5. United Kingdom: England & Wales, 6. United States of America, 7. Singapore, 8. Israel, 9. France, 10. Germany, 11. Malaysia, 12. Ireland, 13. United Kingdom: Scotland, 14. Netherlands, 15. South Korea, 16. Ukraine, 17. Belgium, 18. Australia, 19. Japan, 20. New Zealand, 21. Austria, 22. Norway, 23. India, 24. Italy, 25. Taiwan, 26. Denmark, 27. Hungary, 28. Greece, 29. Canada, 30. Switzerland, 31. Slovenia, 32. Poland, 33. Finland, 34. Sweden, 35. Latvia, 36. Lithuania, 37. Cyprus, 38. Malta, 39. Estonia, 40. Czech Republic, 41. Iceland, 42. South Africa, 43. Spain, 44. Portugal, 45. Luxembourg, 46. Argentina, 47. Romania, 48. Thailand, 49. Bulgaria, 50. Brazil, 51. Mexico, 52. Philippines

(And despite all kind of private browsing modes and no matter how often you clear your browser's cache and history, your own computer keeps a nice track of which Flash enabled sites you visited.)