BBB, McAfee, Nofollow

One of my ideas that I hold is that Google looks at website networks almost as a website in itself--a macro of micros.

So with this in mind,
Do you think it would weaken the bond of association if a membership site like BBB or McAfee linked to me, and I rel=nofollowed my link to them?

Would there be any significant reason to rel=nofollow my link to them in the first place, because in my readings I am coming to the conclusion that adding this nofollow will selfishly retain the juice they pass to me. but this circularly leads me back to thinking that it makes our network bond look weaker because the linking is not reciprocated.

Comments appreciated!

Doesn't seem to hurt Wikipedia any.

Linking out to authority sites that are relevant to the page can help reinforce the topical relevance of that page, so nofollowing those could be hurting your efforts.

If the sites aren't topical, then why would you be linking to them in the first place?

This is what I thought. Thank you.