Ground tracking stations can be attacked and skilled hackers can disrupt their computer systems.

A skilled hacker who wanted to be the world's best, but was overwhelmed by Wrench's skills.

Of course, a skilled hacker would be able to send the program to someone else's computer, perhaps as an e-mail attachment.

The term is a relative one: a skilled hacker may be a user with respect to some program he himself does not hack.

He has been shown in the series to be a highly skilled hacker.

She is a skilled hacker and helped her father provide information on Seventh Heaven for his job.

"If he's a skilled hacker, he may have adjusted the data here and there to suit," McNab put in.

Web-based e-mail accounts like Hotmail have also proved themselves in the past to be vulnerable to skilled hackers.

A skilled hacker however can modify the program so it still works correctly and does what he wants it do.

The other person is a cryptographer-a highly skilled hacker, if you like.