Wolfgang S. Rupprecht:
There are "charging-only" cables that intentionally leave out the data wires. These are a good idea when you don't want some random charger at a coffee shop or airport to download all your pictures and other data while your phone is charging.
Will W:
You are right about that, I completely forgot about that. Thanks for reminding me.
Hmm, if you've got a mixed collection, I'd label the charge-only cables, and save yourself a bit of grief, later on.