Contents farm, scrappers, aggregators real world examples?

Could you plz clarify me:

1. efreedom.com is a scraper site, not a content farm? Because it simply copies and pastes contents from stackoverflow.

2. ehow.com and squidoo.com are contents farm? They don't copy and paste contents they just generate fresh new user generated content, but too much and too quickly.

3. expert-exchange.com is NOT a content farm or a scraper site, right?! It's simply that many people (an me too) hates it (they also wrote to Matt Cutts) because it shows up hight in Google providing a useless question with no answer.

4. There are also many sites that act as 'contents aggregators in the form of specialized directories' (let's call them CASD), I don't know how to else define them. Do they have a specific definition? Anyway are these type of CASD contents farms or scrapers sites or what else? Basically these CASD search for all sites of the same type i.e. “restaurants websites”, they copy and paste the contents found in “Restaurant A” and create in their aggregator site a new page called “Restaurant A”, then they do the same for all websites of the same type, thus creating a sort of directory of restaurants. Later on these CASD also sends an email to the owner of “Restaurant A” (usually the email is on the website) with a user and password to let him modify/update its own page on the CASD site. Later on these CASD might ask for money to the owner of “Restaurant A” because they bring him traffic, otherwise they remove its page on the aggregator. Someone could call these simply directories, but I think a directory is different because is something you need to add your site into by filling a form and not something that steals contents from your existing site without a specific acceptance from the site's owner.

I also really wonder how Google will sort out all these mess sites packed of contents that show up more and more and everywhere in search results.