To throw in further - no one 'owns' the clients. Businesses can't generally control where people choose to take their patronage. However, the business does own the client details, including contact information. It's worth being aware that for the most part, restraining an employee isn't about exercising control over the ability to contact clients - it's more about giving the employer a legitimate head start to re-establish their connection with the client. Bear in mind the 'but for' proposition. But for the employer giving you the job and putting you in a position to work for that client, you would likely not have ever met them in that context.
In accessing and using that information for a purpose not directly connected with that business (i.e. using it for your own purposes) what you've done is essentially: (a) theft from the employer, and (b) a breach of the client's privacy rights. (b) is never likely to crop up unless a client complains and, even then, I doubt the employer is covered by the Australian Privacy Principles due to their likely size.
In accessing and using that information for a purpose not directly connected with that business (i.e. using it for your own purposes) what you've done is essentially: (a) theft from the employer, and (b) a breach of the client's privacy rights. (b) is never likely to crop up unless a client complains and, even then, I doubt the employer is covered by the Australian Privacy Principles due to their likely size.
