[orev]

Your intuition on what’s legal is miscalibrated. Clickwrap licenses have been found valid and have been upheld by courts in many legal rulings. You maybe could have made that argument 15 years ago, but not now. Some are getting to the point where “your continued use of the service indicates your acceptance of the license” is also fully valid.

See the Wikipedia entry on Clickwrap, and Planet Money episode “Surprise, you just signed a contract!”