@revk I'm 100% certain that the previous version of the terms said they could amend them whenever they wanted, and that continuing to use the service after being notified about the change in terms indicates acceptance of the new terms.
What they're doing here is slimy but not likely to be illegal. They have an army of lawyers that made sure of that. People who don't like the new terms can delete their accounts like I did. The company doesn't care if that's inconvenient.