Disgruntled trademark owners have filed hundreds of lawsuits in the United States and Europe claiming that search engines should not be permitted to sell their trademarks to competitors for use as keywords. Despite the volume of litigation, there has been almost no independent empirical work on the goals and expectations of consumers when they use trademarks as keyword search terms. There has also been little or no work on whether consumers are actually confused by competitor-purchased ads. And there has been no reported investigation identifying the types of entities that purchase trademarks as keywords. In this paper, we report on a multi-part study on these issues. We find evidence that many consumers use trademarks as search terms to search only or mostly for products bearing that brand name. We also find evidence of consumer diversion and confusion as to the architecture and labeling of search results. We find that substantial numbers of consumers believe it is inappropriate for one company to buy its competitor's mark as a search term. We identify and discuss how our findings differ from or confirm the empirical assumptions which have been made by judges in reported trademark cases.