I took my laptop to a customer's the other day, ran the Acrylic Wifi checking software there.
When I was finished, closed the laptop but left it running. Drove the 30 miles home.
There is a list of SSIDs longer than all our arms combined - obviously the laptop picked up dozens of home and business SSIDs while driving by.

What has that to do with secure passwords?

In reply to a post by zyborg47:

But you are right it is a good idea to have long passwords.

Try living in a block of flats. I've used 63 chars (the max is not 64) for ~15+ years. I was the first with WiFi in this block using old 802.11b and I try to remember to change my passphrase every 18 months or so.

I'm most disappointed in recent Intel WiFi cards that don't support the update to WPA3, so I'm using WPA2/WPA3 mode on my router. Most consumer hardware has not yet heard of WPA3 !

A comment on the sheer number of Wifi networks visible to the general public.

12 to 15 characters should be enough for a home router unless the Chinese government are picking on your router.

It all works much harder, all sorts of similar methods work well, or can be ruled out as an option! But nevertheless everything is possible!

In reply to a post by E300:

I don't think this is hacking.

The access point following your channel change and picking the same one is not an indication of bad behaviour, quite the opposite if there are no overlapping channels available for neighbouring access points to be completely clear of each other. With no channels available the best choice is for an access point to pick the same channels as a neighbouring access point, this is because when they are both on the exact same channels they can "see each other" and interoperate to avoid collisions. If they are only partly overlapping then they can't interoperate, but still interfere.

I expect at some point during your changes the other access point has chosen a different one to interoperate with and has stuck with that one. I've seen the same behaviour with my own access point.

See https://documentation.meraki.com/MR/WiFi_Basics_and_... for useful info the bit of interest is:

In reference to documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Channel_...:

When two wireless devices transmit at the same time, their radio signals will collide and become garbled. 802.11 devices on the same channel use a CCA check to avoid these collisions. However, the CCA check may not detect a transmission occurring on a different channel that also has some frequency overlap on the channel the check is being performed on. In this case, two 802.11 devices on different channels that overlap may transmit at the same time causing a collision and possible data corruption or frame loss. This is called interference because one device's transmission interferes with another device's transmission.

This is not correct, access points do not base themselves based on a neighbouring access point, the AP is not programmed to say "BT-XXXX" SSID has changed, lets follow it. If anything, if that SSID moved to another channel, it would free up space on the existing channel, and the AP would be happier. APs do not change channel easily, as it can cause user interruptions, the level of interference must be so great it is worth risking clients dropping for a channel to change. Devices choose 1,6 and 11 to avoid the part overlapping and interoperate issue you have highlighted (as I'm sure you are aware).

If you see a device swapping channel instantly, it seems like it's associated with your AP, more than anything.