You can set various levels of privacy in iChat that determine who can chat with you. To set your privacy level, go to Preferences and choose the Accounts pane and then the Security tab.
You can choose from any of these five options:
Allow anyone
Allow people on my Buddy List
Allow specific people
Block everyone
Block specific people
Anyone who is allowed to chat with you can also see your availability (available / away / offline). Anyone who is blocked will always see you as offline.
Shopping online? You can help support Basics4Mac by making your Amazon purchases through this website. Simply click the GO link below and you will be sent to Amazon.com. Any purchases you make at Amazon by going through this site will give me a small commission. It does not affect the price of the items you buy.
Purchase any products from Amazon.com and support Basics4Mac. GO!