Downvoted because it's irrelevant what private companies get up to. At the end of the day they are just that. Private companies. You can choose to do business with them or not.
Data held by the state is obtained under duress. Don't provide it - go to jail. Which is why it's imperative the state demonstrates it takes great care of this data.
Your tax money is the same. Obtained from you under duress. And look how carefully the government look after that. They would never lose that in the Royal Mail. (Although they may lose it in a Royal Mail sale).