That's already in most policies without qualifying it's because they don't like you.

Here's an example:

> We also reserve the right to modify or discontinue the Service at any time (including, without limitation, by limiting or discontinuing certain features of the Service) without notice to you. We will have no liability whatsoever on account of any change to the Service or any suspension or termination of your access to or use of the Service

The right is reserved, no need to give any reason.