What is this hide user identity in error log?

Hello.

What is this code doing in my install? It appears to hide a user sitewide... Further I would like to mail you my error logs. I never thought I would say such a thing, and on top of it actually think you may perhaps enjoy doing so.
lss

(
a.user_id IN ( 0 )
AND
a.hide_sitewide = 0
)