Okay, let's do it that way. I registered an alternate account
Light_Warrior (Alt) and sent a test message to that account. Let the reputable
suchmoon read this message using his BPIP extension. I'll even allow him to post it here in this thread.
Any extension of your browser (theoretically) can obtain data from the pages you visit, be it the BPIP or any other. Fortunately, the vast majority of extensions do not collect information beyond what has been programmed, which guarantees some "security".
The use of extensions should always be done with great care and attention, as there are many malicious extensions. This is clearly not the case with BPIP, which does not record any and all information that appears on the page.