You can serve subpoenas on anyone who has information you need, if you can afford to do this. For a court to issue a subpoena, however, there needs to be some support for its issuance. You cannot just use subpoenas to fish for information. There must be a valid basis.When a company outsources an entire department to a 3rd party.
Is that 3rd party subject to the same subpoena as if they were the company being sued(like an extension of that company) or can this be used to shield incriminating documents/activity?
Some companies might just have a single owner but company has a lot of outsourced parts working together to product a product or service.
You are probably best off concentrating first on your defendant and subpoena what you need from him.