Why should we believe this guy's answers?

Just curious.

I've just come to wonder a lot about sources on the Internet and how the sources can be verified. For instance, I read some pretty interesting information this weekend about clay, I think, and one of the sources was supposedly something that came out of a study done at Harvard. But how would a body know whether that study really came out of Harvard, or was just something put on the Net to appear as though it had come out of Harvard...???