Yes every ISP employee should be behind bars right now
Discussion
Actually, everyone that builds fiber cables should be in jail. And while we're at it, anyone who build cars should be in jail because someone has used them for immoral actions.
Difference is your ISP will actually turn you in to the police on a silver platter if you distribute CSAM. So will every reputable tech company. Actively harboring that activity and claiming privacy rights when the data is plaintext is criminal.