I wanted to delete duplicate bookmarks. Turns out I don't have any, Then I was checking on whether I have FF x64 or 32, which I never installed intentionally. I am fine with x32,. A website I found in bookmarks, about which I had forgotten, is pretty lousy with ads (in spite of Adblock Plus) and will try to bombard you by opening pages you would never click or install, but it made me question JavaScript and Flash, which I updated yesterday. Then I decided to learn about my "about:" settings. Being an utter novice when it comes to understanding any computer language, I didn't learn much. I don't know what Registered Service Workers are, what purpose they serve, how I got them, and why I have them. What permissions have they been granted, essentially without my knowledge? Why these three? Two are websites with which I have logins, but I have many logins. The third is an utter mystery - mainly because I am philosophically and politically opposed to the site. (There are three different urls, but not a live link to the named website.) My options are to update or unregister. Before I unregister, I want to know how they came to be on my Troubleshooting page. I admire and trust Mozilla - I really do. With the news about Yahoo and AT&T, it's utterly hard to trust almost every other corporation. Thank you.