From IRC - #k-9 @ freenode (10/8/22, anomymized), I am <HM>...

<F>HM: if you have a custom ROM with proper iptables support, you could use DroidWall to prevent K-9 from using non-WiFi connections
[...]
<HM>F, *g* I lika that .... cracking a nut with a sledgehammer
<F>;)
[...]
<HM>.oO(I worked with iptables maybe 10 years ago...and I never thought I could use this knowledge on my mobile somdays)
<T>I've seen ".oO(...)" 10 years ago and I never thought I'd see it again. ;)
<HM>ROTFL
<T>wow, and a T in "rofl".
<T>You ARE old skool.

Well, Thanks, I know I'm getting old ;-)