The "net" refers here to "the good that Google does" (e.g., some pretty impressive networking research) is outweighed by "the bad that Google does," such as the linked article.
Nothing is pure evil or pure good. Gauging where on the scale a person or group lies is really hard, and subjective.
So, I try and keep score on the big players, but understand that my judgement is fallible.
Oh I understand what you meant by net negative, I was more curious about the thing's you perceive negatively. I myself consider them net neutral but the trend itself is negative.