A US lawyer can issue a subpoena, without a judge's signature, for documentary evidence or testimony as part of discovery in most civil cases -- if that is your question.
https://www.google.com/search?q=lawy...sue+a+subpoena
A lawyer is an officer of the court that he is admitted to practice in.
You can refuse the subpoena, appear in that court it is issued in and motion the court to quash that subpoena on your argument's grounds.
Websites are liable for their content under the safe harbor that an ISP or OSP (online service provider) has in most cases.
You host will roll over on you if it secures his safe harbor in the action. Throwing you under the bus to save his business' liability is obliviously in his best interest.
I have been subpoenaed before in a matter related to my construction business I owned in the past by a Plaintiff's Attorney as I recall.
*not offered as legal advice -- offered in topical conversation.