Google has human reviewers that will lower your rank for these reasons...

There are those algorithm penalties and manual penalties. Manual ones are usually user reviewed but there are user reviews that never give you an actual penalty, they call these irreversible penalties, meaning even if you submit a site for reconsideration it will say nothing wrong with your site, no manual penalty but your website ranking and traffic dropped drastically, this means scrapers can rank above your for your own content, what causes this is supposedly a human review, either a huge spike in traffic, adsense earnings or clicks, or multiple reports claiming your site is spam or google searchers reviewing your site and saying not a good user experience for them. (usually known as Negative SEO).

I don't know how true this is, but apparently Google has human reviewers now who work for them, this is why they claim only about 15 percent or a small percent of websites will be hit by panda or penguin penalties because not all of the human reviewers for Google can go through the billions of websites daily. So if you are one of the unlucky few who gets randomly picked for a review you are basically screwed and will never improve your rankings again you are not penalized either its just that your site doesn't satisfy the $$$ for Google, google changed their search and algorithm because of money because of Adsense, they want to satisfy the big companies who pay them money to get legit customers and when the spam small sites were spamming they were getting paid but no legit transactions were being done, so the adwords clients and business took a huge loss financially this is the main reason Google changed their search to satisfy the money advertisers. If you notice only the big news sites or blogs with huge traffic are on the first page even when you do exact words searches they will be on the first page. This means smaller sites will never be able to rank high organically anymore they will always be beat out by the huge corps with established names.

What someone told me was if you have a website that all of a sudden gets a traffic spike and high earnings in Adsense, it will trigger a review. If your site is not a huge LA Times site or established site they will lower your rank its basically a penalty without a penalty, your basically lose half your traffic because thy are trying to avoid smaller blogs to earn more money while protecting the interested of the advertisers, this is done because that is how many of the scraper, spam sites were gaming adsense and earning with black hat illegal strategies. Basically small site or niche site with high traffic spike and earnings for that day or week = spam site in googles mind.

A human usually outsourced either located in India will look over your site and lower the ranking if they don't find your site nice looking enough, has nothing to do with quality at all they could just say don't like it and lower it. These employees don't care its too time consuming for them so they will just do a quick glance over and punish your site or not.

This is why you see a lot of scraper sites ranking above the original site, duplicates ranking higher, many of these scraper sites also have nice looking themes even though they are stealing content its because the reviewer says this site looks better he should be ranked higher even though he stole it from another sites content.

people who work at google will tell you this, they will say the reason those scrap sites outrank you is because they are doing it better than you are and that's all google cares about they don't care who wrote what first or published it first. Right there shows they never did this algorithm to catch scrapers because they don't care about it.

If their algorithm was legit than scrapers would be easy to derank its not that hard to do a date posted authority, whoever posts the article first should get ranked higher, simple. but its more so money it has nothing to do with unique content anymore because big news sites post the same article over and over and still rank on the first page..

Look at the highest paid google employees

hxxp://articles.timesofindia.indiatimes.com/2013-04-26/job-trends/38842532_1_larry-page-patrick-pichette-brin


Google's net income gained 10% to $10.7 billion as sales increased 32% to $50.2 billion last year. The compensation increase was especially high in 2012 after the company last year started to hand out equity awards only in even-numbered years, according to the filing.

The bottom line Google doesn't care about you