But I agree that it takes discipline (germans are good at that :o). Gmail, on the other hand, cannot be trusted either. While web.de is evil, google is evil too, but google is bigger and google is not an european company. All of the data is used abroad thus circumventing civilized laws.
The real problem is this: these companies offer a service and everybody expects free services online. Of course the companies have to make money. Ask yourself: would you pay for an email account (I do)? If not, you have to accept ads. Or googles snooping in your data and selling your profile to everyone who pays. There is no free beer online. At least web.de shows us how ugly it gets, if things have to look like they were free.
This is not intended to excuse the primitive tricks we.de uses. But if you have a solution, post it here and I'll get rich.