What is blacklisting?
Misuse of keywords happens where some web developers or other web users use keyword stuffing, which is an expression used to describe when people over use keywords.
This is a bad technique and is picked up by the search engines but can result in penalising and blacklisting by the search engine companies.

Stationery designs to match your website!
Twitter
Myspace
Digg
Del.icio.us
Reddit
Yahoo
Googlize this
Facebook
Wikio