incrediBILL - 1:33 am on Oct 14, 2012 (gmt 0)
It apparently strips the meta copyright tag from pages sent out.
More than likely it's the graphics library, not mod_pagespeed, that strips the meta data. However, that's a simple bug that can be fixed, should be fixed. It's also possible it's just a setting or parameter that needs to be used when calling the graphics library to maintain meta data.
Either way, both are Open Source and anyone here with the skills should feel free to rectify what is most likely a trivial problem. If this bug were fixed once and for all, especially if it's in the graphics library, it would solve the problem for everything that also uses the library.
If I had the time I'd offer to look into the situation, probably no more than a couple of hours from start to finish.