Great Add-on, With Reservations Rated 5 out of 5 stars

This is a great little add-on. I use it religiously now. I have it set so it will delete the LSOs 1 second after they're installed on my machine. That allows the site to THINK it has a cookie on my machine when it, in fact, does not. That works like a charm. No sooner does the Web site install the LSOs (some sites load as many as 11 LSOs per page) than they are deleted.

I also turned on the "Notify if new LSO is stored..." feature and visited a few sites, some of which have NO flash ads, no Flash videos, and no flash games. Almost every site that I visited with no Flash apps on the page still downloaded LSOs onto my machine; so it isn't just video pages, games, or pages with Flash ads that use LSOs to gather info without your permission. Some sites install as many as 11 LSOs per page

I also did an experiment. Using YouTube's pages as the subject, I did a search for videos of a certain song and went to several of the resulting links to test my BetterPrivacy settings and to test the effects of deleting the cookies before, during, and after the playing of a video. I found that deleting the LSOs had no adverse effects whatsoever on downloading or playback of the videos, and had did not affect the functionality of the embedded player.

In seeking out the locations where LSOs are stored, I discovered seven (7) locations, as follows:
Where Flash LSO (*.SOL) Files Are Found in Windows XP:

Not checked by BetterPrivacy by default:
*C:\Documents and Settings\LocalService\Application Data\Macromedia\Flash Player\\support\flashplayer\sys\filename.sol
*C:\Documents and Settings\LocalService\Application Data\Macromedia\Flash Player\#SharedObjects\[alpha-numeric folder name]\filename.sol

*C:\Documents and Settings\NetworkService\Application Data\Macromedia\Flash Player\\support\flashplayer\sys\filename.sol
*C:\Documents and Settings\NetworkService\Application Data\Macromedia\Flash Player\#SharedObjects\[alpha-numeric folder name]\filename.sol

*C:\Documents and Settings\Owner.[Your_Owner_Name]\Application Data\Macromedia\Flash Player\\support\flashplayer\sys\filename.sol
*C:\Documents and Settings\Owner.[Your_Owner_Name]\Application Data\Macromedia\Flash Player\#SharedObjects\[alpha-numeric folder name]\filename.sol

* C:\WINDOWS\system32\config\systemprofile\Application Data\Macromedia\Flash Player\#SharedObjects\[folder_name-ALL_CAPS]\filename.sol

Checked by BetterPrivacy and Objection (default):
* C:\Documents and Settings\Owner.[Your_Owner_Name]\Application Data\Macromedia\Flash Player\#SharedObjects\filename.sol

The file extension for LSOs is ".sol". The files can be deleted manually, and I recommend that users check the directories not checked by default by BetterPrivacy, either by using Windows Explorer to go to those locations, or by copying the file path into the "Flash-Data Directory:" field of BetterPrivacy.

To determine which directory contains the global settings for your Adobe Flash Player, I recommend the following:

Go to Adobe's Web site settings and global settings pages. Delete all LSOs from your computer. Set your global and Web site settings. Search for files with the .sol file extension either by using BetterPrivacy or by navigating to Start>Search>For Files or Folders...>All files and folders> then search C:\ drive for files *.sol (asterisk-dot-sol). Since all other LSO files were deleted before adjusting your global/site settings, the LSO that stores that info should be the only LSO file found. Make a note of the file details (name, location, etc.) and save it into a text file or commit it to memory for future reference. That will help prevent you from having to constantly reset your global/site settings.

Simply opting out or setting the permitted hard drive space to zero will not stop Adobe or other sites from placing LSOs onto your hard drive.

Selecting the "Delete Flash cookies by timer" and "Not if modified within time interval", then setting the "Time interval:" to "1" will allow the cookie to be set, but will almost immediately delete it before any data can be phoned home.

Selecting the "Notify if new LSO is stored" will allow you to count the number of LSOs placed on your machine by any site you visit. For good insight into which sites place LSOs on your machine and how many are placed per page, count the number of warnings that pop up (narrow yellow banner that opens just below the tab bar). Deselecting the "Notify" option will stop the annoying yellow warning banner from opening, but BetterPrivacy will still delete all LSOs as they are placed on your machine.

All-in-all, I really like BetterPrivacy, but I think it should have a feature that allows the user to list several locations to check for LSOs. I also would like to see the option of blocking LSOs from being written to the user's hard drive at all.

This review is for a previous version of the add-on (1.47). 

BetterPrivacy checks all relevant locations, with no exception

The default LSO, located at \\support\flashplayer\sys\ is not deleted with BetterPrivacy's standard configuration, but you can change this setting if desired (see FAQ on details).

Note that all other locations are effectively irrelevant since those are ignored by Flash applications. BetterPrivacy will not waste valuable resources on checking this. For example Windows makes occasional backups of the 'Documents and Settings' files and also includes LSO's which are user data. Thus you may find LSO's in \WINDOWS\system32\config\systemprofile\ or other locations. However they won't harm your privacy - in no way.

The particular advantage of BetterPrivacy is that it does *not* block LSO's from being written (as the Adobe manger does). Blocking has severe disadvantages since the website will know that LSO's are disabled. The same applies to LSO's that are deleted within a few seconds. LSO's often have a useful functionality - so I recommend to (auto-) delete them not before you left the appropriate website (e.g. 30 minutes).

Anyway, there is no capability for a Firefox addon -nor for Firefox itself- to prevent an independent process (flash is a plug-in, thus NOT under the Hood of Firefox !!) from doing anything. Note that any plug-in (not addon) is a potentially very dangerous implementation.