I posted the following in one of the discussions in Apple Support Communities.
I've noticed the iCloud sign on podcast episodes, but I was really upset when I was asked if I wanted an episode from iCloud. No, not really. My iPhone plan has limited download and I don't want to exceed it. This happened at the fitness center, and I clicked OK this time. When I checked with my provider later, I had almost doubled my usage in a couple of days.
Here is a summary of steps for later readers to ensure that your podcasts come from, and only from, your computer:
Select Podcasts on iPhone.I wonder what Joy Mountford, the founder of the Apple Human Interface Group, thinks of the human interfaces of iOS 7 and Mavericks. There is still an Apple Human Interface Group and you can find links to Apple's OS X and iOS Human Interface Guidelines at http://en.wikipedia.org/wiki/Human_interface_guidelines.
Select a podcast
Turn off "Subscriptions"
Set "Refresh Podcasts" to "Manually"
Repeat for each podcast group
These are intended for developers, but I wonder how much Apple follows these for Mavericks and iOS 7.1. For example, from "OS X Human Interface Guidelines: User Experience Guidelines":
"It’s worth emphasizing an obvious fact: Users view your app differently than you do. Nowhere is this difference more striking than in the performance of common app-management tasks, such as finding and opening documents, opening and closing windows, and managing document state. Although there are many ways that apps can make such tasks easier for users to perform, a more important question is, Why should users have to perform them at all?"