<human>: My friend, is in CA and from what I understand Noncompete is illegal. He was fired from the job for working on the side. There was no rule about this or agreement, but that has little to do with the threats. The company wishes to sue him for Missapropriation of Trade Secrets.

The company was in the consumer break/fix IT field and there are no trade secrets related to fixing computers. They are trying to say he has a customer list, he has none, and that he needs to cease using programs (spybot, hitmanpro, malwarebytes) because their usage in a certain way is a trade secret. 

From company "Our "Tune up" service does include free programs available to the public. The specific programs we use, the order in which we use them and the service we provide while using them constitutes a trade secret.  You are barred from using them to provide service to customers"

Also "You must immediately inform the undersigned of the names of Comapny's clients or prospective clients you have solicited or have had commercial contact since terminating your employment with Company."

Which is fine, he has no contact with any customers except for the one that asked him if he performed any side service which lead to his termination. How can they define prospective clients?

It seems to me they are trying to get him not to conduct business in IT aka Noncompete.

See first paragraph of letter sent to my friend

We have become aware that you have formed and are conducting a business identical to Company's business commencing as early as March 2014.  Also, we believe you are using Company's confidential information, software, and methods to unfairly compete in the computer maintenance and repair business in and around Nope, California.  Your conduct is unlawful and must stop immediately.  

If the entire letter is needed please let me know.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Friend being sued for allegedly using customer list, using free programs in a specific manor, conducting a competing business, soliciting prospective clients.