A big part of the security compromise is actually owning a cellphone and carrying it around with you. Unknown people can track you and even listen to every word spoken to it or even near it. That's how you can get targeted ads, even if you're working on a desktop computer.

I refuse to have a cellphone.

Also, it's an extra expense just to allow others to have 24/7 access to you and your time. I like to go places or just go outside and be completely out of contact for a while.