Strange Results
Any good webmaster or search engine marketer should be aware that strange cases can and do crop up. As an example, you may do optimization for a domain registration company and do analysis on your incoming search engine traffic to discover that you rate high on a pornographic term. If you dig into this a bit, you may find that the search result bringing in traffic points to a page of repossessed domains with seedy names.
The point here is that search engine algorithms are indiscriminant in their logic, and occassionally a strange but explainable result may show up that confuses you. Yes, your website will probably rank for a hundred key terms that you’d never think of optimizing or searching for. That is often because the search engine is looking at all of the other content that you might not even think about. So, when your site is showing up on searches for oxycodone, give some thought as to how your use of the word “addict,” even in a different context, can affect its interpretation by nonintelligent search engine spiders.