The Internet doesn't censor your life or filter out items you don't want other people to see. When anyone (including potential employers) plugs your name into Google, the search engine's algorithms deliver the most relevant results.
Relevance is determined by obscure and proprietary secret algorithms. However, the more links that lead to a specific bit of content, the more likely that content will be ranked higher in Google results.
In other words, if the most popular content associated with your name is pictures of you, extremely inebriated and half-dressed at a party, the more likely that content will reflect poorly on your online reputation.
Part of the solution is to load the Web with professional-looking content that reflects well on your name. Keep reading and you'll see ways to make your name stand out, but in a good way.