5 years ago I bailed a long time friend out of jail.  He made a stupid mistake while on vacation in Vegas.  He later told me he had paid a fine and everything was OK,  With 15 years of friendship behind us I never thought about it again until a collections agency from the bond co showed up on my credit report.  As it turns out he never hired a lawyer and just ignored it.  This sort of thinking is probably why we are not friends now.  I had the collections people contact him but I was wondering if it was adventatous to freeze my credit report or add a note to it.  Also can I request my address be changed to a PO Box?  Prior to this incident my score was close to 800 +/- now its around 650 due to this - any advice?