For many years now I've always had the same Adobe ID. I've had different hardware, replacing stuff that became obsolete or that self-destructed.
All the items in question were purchased by me from the same vendor (ibs.it). However, it's possible they were purchased from from different hardware items (any of two iMacs, a MacBook Pro, and/or one or two different iPads) and/or from two different IBS Italia accounts, without my realizing that a second account in my name had been created. (Yes, I "de-authorized" hardware I no longer owned.)
OK. (a) I'm the same person I've always been. (b) I've always used the very same Adobe ID. (c) I've bought every book being challenged from the same vendor. But now? I've spent a fair amount of money purchasing books I'm not being allowed to read. The vendor tells me this is an Adobe problem. Adobe tells me the company has no answer, so I should consult the forums.
I might be a tad slow on occasion, but I'm not stupid. I'll never again purchase a book subject to Adobe DRM schemes. Still, I'm irritated to think I have to write-off the money I've already spent on books i've legally purchased.