I had an interesting situation recently. An ex-client wrote a letter of demand to her ex-partner, but wrote it from us. She created a letterhead, and put our name at the bottom.
Needless to say, the police have become involved. The letter makes serious allegations, and includes a little bit of blackmail. Also needless to say, we will not be acting for her in the future.
Just a bit of a comfort:
Dishonesty offence: 10 years for a basic offence, 15, for aggravated. (max)
Blackmail: 15 years maximum.
The 'client' may be facing charges totalling up to 25 years in prison. The lesson? When a lawyer tells you he won't write a letter for you, maybe there is a good reason for it?