samba log directory

[Christian Christmann <plfriko@yahoo.de>]

Hi,

I just checked my /var/log/samba and found
bunch of log files:

log.shitbanda      log.familj           
log.mario-t3psqfw32  log.talentoaa 
log.syb07	     log.50163099sp
log.gustavo          log.momerdadd        
log.rampeiras        ....

When I understand samba correctly, it
creates for each user who is trying
to use my samba server a separate
log file. But why do I have all these
files from users I don't know?

Did these guys try to break into my linux
box? 
If so, how can I recognize if they were
successfull?

Thanks,

Chris