It struck me as odd, till I thought about it.
You take a mage to prison, yet they are not as penalized with their weapons removed. It barely affects most of them.
Now considering how little modern nords care or know about magic, it doesn't surprise me that mages don't get gagged or given anti-magicka cuffs to prevent spell casting (like morrowind)
It just made my hesitation to do certain quests go away, where my warriors and thieves are in a bind in Markarth... my mage is going to be just fine!