Meta Tags are present (hidden in the html) at the top of most web pages. They are used, amongst other things, to provide a description and/or keywords to Search Engines and Directories. They are now largely ignored by the Search Engines due to frequent abuse.

You may find that your competition have inserted your product or company name in the meta tags with a view to poaching some of your customers or potential customers. The best way to tackle this is to contact the offending company and ask them to remove the references to your tradenames. There may, however, be legitimate reasons why your trade names appear on their web site. Perhaps they are making a comparison between your product and theirs. The usual laws of business apply. Can you show they are making any untrue statements. In some cases these could be construed as "malicious falsehoods".

There is much more information regarding the legal implications surrounding meta tags on the excellent SearchEngineWatch web site at http://searchenginewatch.com/article/2064919/Meta-Tag-Lawsuits