Clippings collects web page text that you select for the purpose of giving you the ability to paste it later into web page forms. As a user, you have full control over what data you want to save, and you have the ability to add, modify or delete it.
The data that is saved by Clippings is stored in an IndexedDB database located in your Firefox profile folder. Your Clippings data is NEVER sent to its creator/maintainer or any third party service, and ABSOLUTELY NONE of your data you choose to save in Clippings is shared for marketing, statistical analysis, user surveillance or any other purpose.
 More information on Sync Clippings: http://aecreations.sourceforge.net/clippings/sync.php