Calendly

"Calendly reserves the right to investigate complaints or reported violations of our terms or policies and to take any action we deem appropriate, including but not limited to suspending or canceling your account, reporting any suspected unlawful activity to law enforcement officials, regulators, or other third parties and disclosing any information related to your account and or use of the Services that may be necessary or appropriate to such persons or entities including but not limited to name(s), e-mail addresses, usage history, posted or solicited materials, IP addresses, and traffic information, or other Customer Data, or Personal Data as described under our Data Processing Addendum or Privacy Notice."

Calendly can suspend or cancel your account and share your data with law enforcement or regulators if they suspect a violation of their terms.

Your account could be shut down, and your usage data shared externally, based on Calendly's interpretation of their rules.

"If we make any material changes, we will use commercially reasonable efforts to provide you with advance notice prior to the change taking effect. You can review the most current version of the Terms at any time by visiting this page. Any material revisions to the Terms will become effective on the date set forth in our notice, and all other changes will become effective on the date we publish the change."

Calendly can change its terms with notice for material changes, but can update any term instantly on their website for non-material changes.

You might agree to one set of rules today and find them changed tomorrow without realizing it.

"If you access or use the Services after the effective date of any changes, that access or use will constitute your acceptance of the revised Terms. If you don’t agree to be bound by the changes, you may not use the Services anymore."

If Calendly changes its terms, continuing to use the service means you automatically agree to the new rules.

You could be bound by new terms you haven't read or don't agree with, simply by continuing to use the product.