Opt out decloartion
Have your subscribers send the following once a calendar year to Google / Alphabet legal department
Any information collected by software provided by Google/Alphabet, it’s affiliates or content providers for the engagement of services, required to accesses services, purchase of a goods or tangible assets through or facilitated by your organization may only be used for administrative purposes as defined by commonly accepted account principles and for the delivery of the said services, goods or assets. It may not be disseminated, distributed or disclosed to any party or used for any other purpose without the prior written consent of the person the information was entered by. Consent must be in the form of a written document delivered to your CEO by registered mail the costs of which are paid in full by Google its agents, assigns, designates or affiliates. This supersedes any permissions implied or assumed that your organization feels it may have been given because a web page, e/mail, service or other electronic documents from your organization were or may be in the future accessed directly or indirectly.
They have a choice of withdrawing their services from the user, or responding in writing requesting an exemption which the user must not grant. And if they deny services to the user who has a contract with a third party who has “contracted” Google / Alphabet; Google / Alphabet is in breach of contract and action may be taken against them for that breach.