Search engines may penalize sites they discover using black hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.[53] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's list.[54]
This topic seems actually quite controversial. Google answered the question by what could be taken as a denial. But their answer was kind of open to interpretations. And on the other hand, there are studies (one of them from Moz) that showed linking out has an impact. So, how can you be so assertive? Is it something that comes out from your own experiments?

Chrys was bitten by the entrepreneurial bug at an early age. At age 10, she bought soccer cards in bulk and sold them in school. Later, she turned down a university scholarship and moved to Thailand to start an apparel business. By age 27, she started and ran two online businesses while living around the world. She now runs Chrys Media, an educational company that runs online conferences, courses, and workshops for entrepreneurs and marketers.

As an Internet marketing strategy, SEO considers how search engines work, the computer programmed algorithms which dictate search engine behavior, what people search for, the actual search terms or keywords typed into search engines, and which search engines are preferred by their targeted audience. Optimizing a website may involve editing its content, adding content, doing HTML, and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.[3] In 2015, it was reported that Google is developing and promoting mobile search as a key feature within future products. In response, many brands are beginning to take a different approach to their Internet marketing strategies.[4]
This is a crucial area. If you do not have schema markup and rel="author", you are costing your business money. It is as simple as that. As an example, say I want to make spaghetti (pasta) for dinner I search for “Spaghetti Recipe” and instantly I see some great markup in play, but one competitor has no markup and no rel="author" they are losing business in my eyes. Wouldn't you agree?.
Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using metadata to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[10][dubious – discuss] Web content providers also manipulated some attributes within the HTML source of a page in an attempt to rank well in search engines.[11] By 1997, search engine designers recognized that webmasters were making efforts to rank well in their search engine, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings.[12]
Well, yes and no. Sure, you can get hit with an algorithm change or penalty that destroys all your traffic. However, if you have good people who know what they are doing, this is not likely to happen, and if it does, it is easy (in most cases) to get your visits back. Panda and Penguin are another story, but if you get hit by those it is typically not accidental.