Lack of content?

To me, yes.
Or when there's one paragraph (sometimes stolen from elsewhere) and (normally) the max amount of adverts allowed, framed around the little/no content.

I saw a site the other day that had 3 rows of skyscrapers before you got to the "content"... which was little to say the least.

Lack of a privacy policy?

I wish. I could get tons of accounts closed if that were the case.

Lack of content and/or stolen content, maximized ad usage.

Lack of a privacy policy?

I wish. I could get tons of accounts closed if that were the case.

I've tattled on AdSense accounts with illegal/mature content and high traffic, but Google just ignores me so I don't bother anymore. Congrats if they actually listened to you.

Most of the time they listen.
In most cases I think a warning should be done, even if they break the TOS [except MFA sites]. Give them a day to fix it, then if nothing done, ban them.

Personally, I think parked domains and blogs should not be allowed adsense, but that's another thread.

As Lame_Wolf pointed out, typical violators may place three (or more) skycrapers, 728x90s, 336x280s, or 300x250s at the top of the page. All of these are positioned well above very little, if any, content.

I know Google's algorithms are considered ingenious, but I have no idea how an automated process can detect these sites--especially when considering the multitude of sites that are "CFA" - (Changed for Adsense). In my opinion, CFAs are sites that existed without Adsense, but have gone through complete design changes to accommodate ads.

I'm not sure how Google can tell the difference and it probably doesn't matter since ad location, and lack of a privacy policy seems to be the glaring issue. Either way, it can't be easy to detect a site whose owner has two or three legit sites with good content, but also holds 50+ sites with little or no content.

Maximized ads would be three banners and three text links. But who really uses the max allowed?

if(ads_on_page >= 6) {return manual_review();}

This alone would get rid of 90% of the MFA sites.

But who really uses the max allowed?

I have seen a number of these. I don't have a list, but do come across them. But most have scraped, hotlinked, little/no [original] content.

What do typical MFA sites look like?

• very common design (most use free templates you can see elsewhere)
  
• mostly Wordpress blog look, to me WP has become almost the signature of copy&paste
  
• no people at all on the pictures (general pics). I've come across a lot of wordpress about travel copying images from galleries and writing some text "blah blah come and visit this place"
  
• The "VIA" credit: lots of content thieves just copy and paste the content and put "via webmasterworld.com" and have zero original content
  
• Not a general rule but I've seen a lot of sites with PR 1 or 2 and high alexa rank, and yes, MFA
  

In general, copied content.

if(ads_on_page >= 6) {return manual_review();}

my guess is that this filter would yield significantly more false positives than actual MFAs.

we have many pages that have lots of textual content. of course we could paginate, but we have opted not to for SEO reasons. in many of those instances, we would prefer to use more than the 3-link-unit/3-ad-unit maximum. on some pages, we could put 10 ads, and i bet that no one would say that the pages looked even remotely spammy.

"Lack of a privacy policy?"

Are you serious? What percentage of legit (non MFA) sites have privacy policies? I'm surprised anyone would look to privacy policies as an indicator of quality.

MFA are sites with too many ads, ad blocks in the middle of the text, and copied content.

What percentage of legit (non MFA) sites have privacy policies?

All of them should have a privacy policy online.

All sites running AdSense are required to have a privacy policy, and to keep it up to date.

Beyond that, if AdSense is running a "War on MFA sites" it sure is hard to see any positive results if we take the complaints seen in this forum as evidence of progress in the battle.

I fully agree with ken_b.
I have one competitor who has got domain name similar to our site but absolutely no contents whatsoever.
I have complained to adsense through my adsense account about this site many times.
But still that site is showing google adsense and nothing else.
The last complain was made about 6 months back. So i think sufficient time has passed.

Rajiv

Even as bad sits MFA have impact on the advertisers and price of the ads, every click (no matter where) means earnings to Google. If MFA had a real short term bad impact on G they could care more.