Now google trying to create an encyclopedia

Google is trying to be alternative for wikipedia by creating web pages on http://knol.google.com/
But unlike wikipedia, where people can write anything as a anonymous user, google wants people to know who has written the contents, so that is becomes easy for people to believe in the contents..
But what i liked here is, google has come up with a revenue model for writers, google will place ads on the pages of popular writers and will also pay to those writers.
i hope this is going to make large hits on google..
But i don't know how google is going to make sure that the contents are originally written by the writer who posted it?