> This might be an android thing only, but when I type, for instance "sea", the URL bar autocomplete will suggest "sears.com", even though I have search disabled and have never visited sears.com. There are a bunch of these which seem to have come out of nowhere.

I honestly never noticed this, because I look at the keyboard when I type a URL on Android.

Doing a bit of research in Bugzilla, it appears that there are two different systems in Firefox to "seed" the browser with autocomplete results. The first was implemented in Fennec (Firefox Android) [1] and acts as a fallback to the Alexa top 500 sites if no other autocomplete result was found [2]. The second was implemented separately in all of Firefox [3]. Ironically, someone was worried whether this might appear to users as a paid advertisement, but proposed using engagement as a metric to measure the impact [4]. That implementation uses browser.urlbar.usepreloadedtopurls.enabled and .expire_days to stop using the preloaded list after two weeks (when the user probably has generated enough history of their own). But the earlier Fennec version doesn't respect those settings. Someone already complained about that [5], but it doesn't appear like they filed the report in the right place for someone on the Fennec team to see it.

I'm going to file a new report to hopefully get that fixed. In the meantime you can toggle browser.urlbar.autocomplete.enabled to completely disable autocomplete, but I guess you might not want that if the suggestions are otherwise useful.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=858829

[2] https://hg.mozilla.org/mozilla-central/file/tip/mobile/andro...

[3] https://bugzilla.mozilla.org/show_bug.cgi?id=1211726

[4] https://bugzilla.mozilla.org/show_bug.cgi?id=1211726#c10

[5] https://bugzilla.mozilla.org/show_bug.cgi?id=1211726#c70