Have you ever received a letter or email from your bank, insurance, or financial entity informing you that they share various types of your data with other parties?
Then they ask you to call them in order to stop them from sharing your data.
How about we just prohibit them from sharing our data in the first place?
In this case, it is better to ask for permission than to ask for forgiveness.
It should be made clear (short and simple) up front, when you need to accept terms and conditions, what types of data they collect and how they plan to share it.