Where actual trademark confusion is not likely because one party uses disclaimers or other information making clear that the mark in question is not related to the senior user's mark. An example is where a domain name that is the same as someone's trademark lures people into the competitor's site, but once on the site the browser sees clearly that the site is not the same party, and there is no actual confusion after that point. If the site which lured the browser with a deceptive trademark sells competing products, then the site is problematic for the senior trademark user, and may be actionable.
