etailology

MetaJacking equates to keyword-theft.  It is when you do the following:

1. Search for the product or service you sell.
2. Identify the top-ranking site which is not your own.
3. View the source code of their page.
4. Copy their meta-keywords tag content.
5. Paste that content into your own site.

In theory, MetaJacking should not have a dramatic impact on your own search engine performance, but you can think of it as a slimy tactic with which to improve your standings.  I don’t recommend it, but it might happen to you.