Ethical Disclosure of Professional Knowledge in PhD Dissertation
I've known cases where the thesis itself has very restricted circulation for a fixed period (e.g. six years) after completion, to protect the commercial information that went into it. The restriction also meant that papers couldn't be published on the back of the PhD research for six years, too.

That was an arrangement made early on during the writing of the thesis, and it enabled the use of a lot of information that would otherwise have been out of bounds.

That's potentially quite an impediment to one's career, so one would have to get good advice on whether it was a price worth paying. But it doesn't make an academic career impossible: I know of at least one successful academic who's take this path - she's an exceptional talent, and so it's no surprise that her path has been exceptional. It does put an emphasis on diversifying straight after the PhD, to gather material for new publications. Diversification can be a good thing: lots of new post-docs get typecast and trapped by and in their PhD subject.