The BBC is reporting today that the UK govt have installed spam filters that have used keyword blocking and the result has been lost communication about an upcoming Sexual Offences Bill.
It's interesting for us because we filter all the governments email, so some people immediately thought that it was our (my) filters at work. Luckily no - it was "Content Technologies" aka MailSweeper they were using - a server side component that offers keyword filters for detecting spam. The govt only buys virus filtering from us.
Sounds like a sales opportunity to me