There is another side of ToS in the Netherlands that I haven't mentioned: The ToS has to be reasonable. There is a blacklist which cannot appear in a ToS under

There is another side of ToS in the Netherlands that I haven't mentioned: The ToS has to be reasonable. There is a blacklist which cannot appear in a ToS under any circumstance because it is unreasonable to ask from users. For example, it is illegal for a company to require users to agree that when they buy goods from their shop they cannot return it whatsoever. There is also a gray list: these are conditions that companies may ask users to agree to if and only if they can prove it is reasonable condition. Notice that this a reverse of the burden of proof: normally a user has to prove that some terms in the ToS are unreasonable which is hard. Now the company has to prove that their terms are reasonable, which is also hard but better for the user. For example, it is illegal for companies to document the religious beliefs of a person BUT if this is a service for certain religious community (e.g. a forum for a church) then the term that they have to disclose their religious belief is reasonable (given that they don't share this information with anyone, of course). As for the ads, I don't know. It might be unreasonable to have users agree to subject themselves to third-party ads in order to use the service. But again, I am not a laywer.