There have been five reports in the last two weeks from users on German Wikipedia that they've received at least one "false positive" message from LoginNotify.
The purpose of this ticket is to figure out whether there's an unexpected problem, and if so, what we can do about it. There's one report on Meta, and then I found two discussions in German which I Google translated. Below is the info that I know.
#1. Ibn Battuta reported on Meta: "Other users and I have been getting loads of false positives: warnings that a different device was used for a log-in when in fact we were using our same computers all along. Maybe the IPs have changed, but certainly not the devices. So, first, the email notification text should be adapted to properly describe whatever it's supposed to be warning about."
I've responded to Ibn Battuta on Meta asking for more info.
#2. This discussion has two people who've received false positive messages: RookJameson and Alexpl.
RookJameson says (G-translated): I received an e-mail a few days ago, that someone of a new device with my user account has registered. Since I have not done this, I have carefully changed my password, even if no foreign edits were carried out or the like. Today I habitually inadvertently first my old password enter and then a Wikipedia internal message that a failed log-in attempt of a new device took place. At the same time, I also received two e-mails from a failed and a successful log-in of a new device reported. It seems to me, for some reason, my laptop, with which I have been editing here for years, has recently been recognized as "new".
Alexpl says (G-translated): It happened to me. Same computer, same software - three messages about supposedly "new device".
#3. This discussion has two people who've received false positive messages: WIr lagen vor Madagaskar and Benatrevqre.
Here's quotes from that discussion, Google-translated:
WIr lagen vor Madagaskar: Could someone stop these wikimedia mails to my email address? It's been the same PC for years... I have already tried cookies, it is not. Also my tracking blocker does not increase its counter when I log on. To any information on my PC, wikimedia does not seem to get any more.
Benatrevqre: New IP address and / or other browsers used?
WIr lagen vor Madagaskar: Googlemail does not seem to know my PC any more and therefore sends warnings. Google and wikimedia seem to use the same sniffing technology. But which?
Benatrevqre: I guess you have recently been assigned an IP from a new and completely different address range.
WIr lagen vor Madagaskar: Would be an explanation. If my network operator in my router exchanged the address of the DNS server entered therein against that of another DNS server, and wikimedia can query, which DNS server belongs to my dnamische IP, something like this could come out. They would not have to start a snooping script on my computer. But, nothing exact is not known.
Benatrevqre: With the DNS server has nothing to do. I am also with a Provider for a long time customer and could also notice the same phenomenon.