Ben Hammersley makes some good points about the tight relationship between a blog - even a private one - and the blogger's employer:
But it brings up an interesting point about the position of the employer over an employees personal weblog, when that weblog talks about the same work that the employee is paid for. There's a very strong case to be made for an employer's control over such a weblog, even if it is written entirely outside of company time. Why? Well, a personal weblog on a professional topic creates a whole new balance of power between the employer and the employee. Both gain reputation from the blog: If average person x blogs about his work at hot company y, person x gains hotness from that company. If hot person a goes to work and blog from average company b, the company gains kudos in return.
This requires a balance. A weblog is a long and powerful resumé, and no matter how little Niall, say, might mention it, his reputation is ever increased by his overt relationship with his employer. His own personal brand and that of Technorati are forcibly linked in public by his own choice.
This all falls out of this incident, wherein Niall was asked by his employer to remove a posting.