Yes, absolutely. That's part of the technical risk that you take if you decide to do such things.

If it's a "good" choice or not is entirely situational. Some organizations are fine with kicking that tech debt down the road, others like to double down and create a house of cards. 

On Thu, Feb 1, 2024 at 2:21 AM Frank Habicht <geier@geier.ne.tz> wrote:
On 01/02/2024 01:45, Tom Beecher wrote:
> Seems a bit dramatic. Companies all over the world have been using other
> people's public IPs internally for decades. I worked at a place 20 odd
> years ago that had an odd numbering scheme internally, and it was
> someone else's public space. When I asked why, the guy who built it said
> "Well I just liked the pattern."
>
> If you're not announcing someone else's space into the DFZ, or
> otherwise trying to do anything shady, the three letter agencies aren't
> likely to come knocking. Doesn't mean anyone SHOULD be doing it, but still.

Well...

If you're using 20.20.20.0/24 which is not "yours" (as I've seen
happen), then certainly your customers can't get to the real 20.20.20.x
And even if that's not announced and used /today/ - this can change
quickly...

Frank