Should I accept friend requests on Linkedin.com from people I have never heard of?

I know that on some Social Media sites like Twitter the whole game is about getting as many people to follow you as possible. There, having people become “Friends” when they don’t really know you from Adam is a good thing.

I’m not sure about a site like www.Linkedin.com. With its business oriented mission, having a large group of friends seems a good thing. But when you accept friend requests from people you actually have never heard of before, you give them a tiny share of your own credibility. What if they turn out to be total rip-off artists and one of your real friends trusts them in a business deal partly because they saw that the two of you were connected on Linkedin?