While it is true than many SEO companies are running a scam, there isn't any evidence that most are using unethical techniques unless you are specifically referring to the many companies who are scammers. Anyone who refuses to tell clients what they are doing or cites "proprietary techniques" is probably using black hat SEO or running a scam.
Originally Posted by Natural Elements
The biggest problem that I see over and over is with the companies that charge hundreds of dollars each month for SEO services, do nothing to a optimize a client's web site and at best set up a few weak links to the client's site. I've been involved with SEO for 14 years. I put the percentage of scammers at around 60%. It certainly is not 95%. There are a lot of companies who do a good job and are strictly white hat.
Personally, I would not trust the people who wrote the article. That in itself appears to be a scam.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin