In Germany, 70 percent of those looking for information online use Google. That's got a few European media experts worried that the search giant might come to abuse its power by manipulating results, which is ridiculous if you believe Google stands by its user-centric search ethos and "don't be evil" corporate mantra. The big three make up 90 percent of German searches--a troubling sign, says Marcel Machill, a journalism professor at the Leipzig and Dortmund universities in Germany. "In the classic media sector this kind of concentration would be unthinkable," he said Tuesday, after a two-day conference in Berlin. "It is important not to let this power develop unobserved." He added that Google has a responsibility to police its own content in the interest of local law--for example, Machill said it should not so easily allow access to illegal Neo-Nazi sites. He added that government needs to stay aware of how the search companies operate, and regulate them if need be. Meanwhile, search engine companies voluntarily agreed last year to filter sites with x-rated content or that glorify violence out of their results. Other speakers said this represents nothing more than "weak regulation without any sanctions." Google representative Stefan Keuchel countered by saying: 'We believe in freedom of expression, not censorship." He added that there is no reason to fear Google manipulating search results, because they are determined by a mathematical equation.