Word verification

Bloggers will be aware of word verification - to prevent blogs being hacked and to prove there is a human being trying to leave a comment, not a malevolent artificial intelligence.

I assume the 'words' are created randomly - or are they?  I only ask because I was commenting on someone's blog the other day and the word that came up for verification was 'NONCE'.  For non-UK readers, I should explain that 'nonce' means :-

a deviant, a sex offender;
from acronym NONCE, UK prison classification for prisoners deemed at risk from attack from other 'regular' prisoners because of the sexual nature of their crimes 
I showed it to the wife and she said 'sounds like they know you well'.

Thanks, love!