Is that how depositions work though? Being deposed means being asked questions in a very official manner by opposing counsel. During discovery, they can issue a subpoena/warrant which gives them permission to take your possessions.

Or you could just get really drunk and lose your phone. Happens all the time. The phone company will verify you called for a replacement and the bar will verify you got trashed.

IANAL but this strikes me as bad advice.

IANAL, but isn't that obstruction of justice and/or contempt of court?

Yes, probably. That would presumably be why this suggestion includes details that would make proving your intent difficult.

> Telling the courts/lawyers to piss off is not a viable option. That's not how depositions work. You might be able to get a lawyer to file legal motions with expert testimony attached pointing out they shouldn't need access to the whole phone for the reasons you said, but 99% of people will not bother getting a lawyer for something like this.

No, that is now how subpoenas and depositions work. I've been involved in a few. The judge needs a specific reason to approve inclusion of your personal device: like a record of information having been sent to it specifically or being used in a context relevant to the case at hand. And the information request will have to be specific to the case at hand, so you can just return with "There is no information on those devices relevant to the subpoena parameters" (said under oath).

If they demand your personal device anyway, because the subpoena is too broad or something, you can fight it with the judge and argue why it shouldn't be included.

If you never, ever mix personal and work then you should have no difficulty getting your personal devices excluded from a work related inquiry.