Was it legal "to take a closer look and see the links they are sharing"?
The ToS also includes this:
> You represent and warrant that: […] the Content will not or could not be reasonably considered to be obscene, inappropriate, defamatory, disparaging, indecent, seditious, offensive, pornographic, threatening, abusive, liable to incite racial hatred, discriminatory, blasphemous, in breach of confidence or in breach of privacy; […]
For which they obviously need to look at the data.