Honestly, I don't understand why it's a perk. A great deal of the npcs don't actually wear their clothing, it's just part of the character model.
And every single character wearing something unique or hard to find is like this. The only people you can reliably steal the clothes/armor from are guards, beggars, & priests.
So why give me the ability to steal things under certain circumstances, but disable that ability on the rare occasion I have reason to use it?
Why is the only clothing I can expect to be able to steal guard armor, rags, & ugly brown robes?
This the third or fourth pickpocket focused character I have made, & it bugs me more, & more each time.

Completely agree. I was disappointed to learn most of the unique clothing, save for Bryling, was unobtainable.

Even Bryling's rests on a glitch though.

I use it when I decide to have a little fun buy going to jail. Disarm the gaurd and steal his armor. For fun really I guess.

It isn't to be used seriously

You can have fun stealing the clothes of everyone in skyrim.
It is especially funny when they say...
'You and me are the only people in Skyrim who aren't complete fools'

I agree, however it doesn't change the fact that the perk is quite useless if I can't steal nothing valuable as a thief.

It is useless but in a way not, you can weaken someone greatly by stealing their armor or weapons but yea, most people just do it for the lulz.

this perk would be good if you pick the unobtainable clothes like greybeards robes

was just coming in here to say this, its a good way for a theif character to gain an edge in combat if its combat skills aren't up to snuff, along with the poisoned perk its a great way to gimp enemies. Yea, it is mainly used for fun though.

If you take all of their clothes...where do you put the poison?

well you sneak up from behind them so...

I used to be an adve...HEY, what was that?

ha nice, too bad you cant name poisions...i would make "aenema of destructive bowels"

Honestly though, most enemies have such pitiful armor ratings that it isn't much of an edge.
If I take this fella's studded armor before I kill him, he stills goes down in one sneak attack, maybe two if I'm unlucky.
And in a fair fight it take nine slashes as opposed to eleven.

Picking their armor really doesn't change much of anything in combat.