Comments/Ratings for a Single Item

What would be wrong with putting a length-limit on user ID's to prevent
this problem from recurring? Perhaps characters like at and slash should
be prohibited as well.

They aren't garbage characters. He is giving his name in Chinese (or maybe
Japanese). You may need to install a Chinese font to see them
appropriately. Still, the name field should be used only for names spelled
with alphabets that are rooted in the same Latin alphabet used for English.
It shouldn't be used for URLs or for names spelled with non-Latin
character sets, such as Chinese, Russian, Hebrew, Arabic, etc. The reason
for this is that this site is in English and is run and frequented mainly
by people who speak English as a first or second language. And most of
those whose first language is something else, such as Dutch, French, or
Spanish, still use the Latin alphabet for their primary language. So, to
give the majority of people here an idea of how to pronounce your name, it
should be given in Latin characters, transliterated if need be. For
example, this person might put the Pinyin transliteration of his name in
his name field, then use the 'Notes' field of his user information to
give his name in Chinese, and 'Web site' field to give the URL to his
website.

Thanks, I corrected my name. But I only used my first initial, and I put
(zzo38) at the beginning so people don't think it is someone different. I
put my name in Japanese in the Notes field, and my web-site in the web-site
field. (I am not really Japanese, I just like to put it in Japanese, maybe
you can read it!) If you want my whole first name, or anything else
different, you can comment on it here and I will correct it more.

Thank you very much.  This is a big improvement!  I appreciate it.