> Your program will suddenly generate an error when faced with this data and your user will be unhappy.

Hmm. Let's see here...

>>> a = [u'ÞORN', 'PORN', 'YARN', 'ZEBRA', 'TOUHOU', 'TANK', 'PRALINE', 'PAGAN', 'THEME', 'TITMOUSE']
>>> a.sort()
>>> for i in a: print i

...
PAGAN
PORN
PRALINE
TANK
THEME
TITMOUSE
TOUHOU
YARN
ZEBRA
ÞORN

Oh look, no error.

And suppose you wanted to make an alphabetical index:

>>> for i in sorted(set(i[0] for i in a)): print i

...
P
T
Y
Z
Þ

Still no error, and it works fine. Now if you were just blindly manipulating strings, as you suggest, you would have a problem, because you'd be dumping the first byte of a multi-byte character. But you're right! Why would people need to see the entire letter anyway? They can just guess.