taribo

Hi everyone,
I wanted to ask peoples' opinions about something.
I was running some domain names today looking for availability in .com and .co.uk extensions. All of the names were generic two-worders.
What I found was that there were a number of names which had been registered as .co.uk but not as .com.
So my question is, what do you think about the legitimacy (or not) of registering the .com version and then offering it to the .co.uk owner?
All opinions welcome.