If a party owns the rights to a particular trademark, that party can sue subsequent parties for trademark infringement. The standard rule is “likelihood of confusion.” To be more specific, the use of a trademark in connection with the sale of a good constitutes infringement if it is likely to cause consumer confusion as to the source of those goods or as to the sponsorship or approval of such goods. In deciding whether consumers are likely to be confused, the courts will typically look to a number of factors, including:

1. the strength of the mark;
2. the proximity of the goods;
3. the similarity of the marks;
4. evidence of actual confusion;
5. the similarity of marketing channels used;
6. the degree of caution exercised by the typical purchaser;
   the defendant’s intent.