Pros and Cons of Buying and Redirecting Keyword Rich Domains

I'm looking for peoples opinions on the practice of buying up keyword rich domain names and then simply 301 redirecting to a main site. E.g. An online music store might buy up a multitude of domain names that include various instruments (guitar, piano, keyboards etc.) and then 301 each of these to their primary website.
My thinking is that when the big G becomes aware then the primary site might find itself penalised. What are your views or do you have first hand experience of this practice actually working?

 

They know about everything and they are watching our site continuously so if anyone do unethical SEO surely they will banned (Penalized) the site.

 

Here's the answer http://www.searchenginecollege.com/2006/10/q-and-could-purchasing-and-redirecting.html

 

Thanks for that link - That was my opinion although I disagree with this statement from that post:

Thanks for the pointer -