Hey, it's what they DO! Chewing keeps their teeth sharp so they can destroy all that wild prey in the world, don't you know??
The ONLY way you can have them not chew what you don't want them to chew is keep it out of their reach. Think about it like "baby proofing". You wouldn't leave stuff on the floor you wouldn't want a new crawler to get ahold of, would you?
Also, provide them with chew toys and treats that they love love love, and they may leave your stuff alone.
It's all up to YOU!