Quoted from ForceFlow:

Personally, I wouldn't bother to respond because it doesn't sound like a request with any legal backing--it sounds like simple dredging and information gathering where Elaut is hoping to turn over a few rocks and possibly find something they can use in their lawsuit.
I'd guess this fishing expedition means Elaut hasn't really found anything yet. It sounds very unusual to me for a request like this to be sent out to past customers.
Unless JJP supports or encourages the idea of folks handing this information over, I wouldn't bother to do anything (unless buyers become legally obligated to do so). If JJP was requesting the information as proof of what you paid to JJP, then that might be a different story.
Disclaimer: I'm not a lawyer...just a guy with occasional bouts of common sense.

Quoted from pinballcorpse:

I agree they could issue one, however it seems doubtful counsel would serve a consumer knowing the requested documents are probably not in the consumer's possession.
Further, it seems there would be little legal expectation for a consumer to actually have a receipt or the financial records. I'd be surprised if a consumer would be in contempt of court for failure to produce a receipt or credit card statement showing they purchased an item 4-6 years ago.
Is there any precedent for this?