Flash cookies are a new way of tracing your movement on the Internet and storing lots of information about you. Their official term is Local Shared Objects (LSOs) and their primary purpose is not to track you, but to provide Flash applications with options to save data to the local system.
This can be useful when you play games, as it is one way to save your progress. But since there is no distinction between good and bad uses, many companies have started to use Flash to save persistent information on the user system as an alternative to third-party HTTP cookies.
One major disadvantage of flash cookies is that you can't locate them in your browser easily. They are not shown in the list of cookies which you can access if you open the cookie manager of the browser, nor do they appear in databases or other browser-specific storage locations.
Normal HTTP cookies can't save more than 4 Kilobyte of data while Flash cookies can save up to 100 Kilobyte by default. If you want to try out how they work you could do the following.
Go to YouTube, increase or decrease the volume of a video and delete all cookies afterwards. You will notice that the volume level is still at the same level when you close your browser and open it again.
This is done with so called Local Shared Objects, better known as Flash cookies. The main question is of course how a computer can be checked for Flash cookies and how you can delete these cookies on your system to reduce the exposure to tracking.
This is actually a very tricky thing. I was looking for a way to check them on my computer but could not find one.
After several hours of research I found information on the Adobe Flash Player website that helped me figure it out. You need to open an online page on the Adobe Website, the Adobe Flash Player Settings Manager to be precise, to manage and delete Flash cookies on your system.
The so called Settings Manager can be accessed from the Adobe website but is running locally on your computer. The Website Storage Settings display all Flash cookies that are currently saved on your computer.
You can delete flash cookies from individual sites or all at once. It is also possible to increase or decrease the Kilobyte size of all information that are stored on your computer.
Adobe does not have access to the settings that you see in the Settings Manager or to personal information on your computer.
No Flash Cookies will be saved if you go into Global Storage Settings and disable the option "Allow third-party Flash content to store data on your computer".
47 websites did store Flash cookies on my computer and I decided to delete all of them and disable the feature to be on the safe site. Did you know about Flash cookies ? How many did you find on your pc?
Update: The most recent Flash versions, at least on Windows, make available the settings manager locally as well. Open the Windows Control Panel and locate Flash there. When you open the applet, you see the storage settings right away.
Here you can click on delete all to remove all information from your computer, or open the local storage settings by site menu to get a list of all websites that use the storage.
Not all use the storage to save cookies though, and you may want to go through the list to avoid deleting data that you may need in the future.
Switch to the advanced tab afterwards. Here you find another option to delete all browsing data and settings on the computer.