Welcome to WebmasterWorld Guest from 126.96.36.199
>>>Can you sue someone spam your guestbook, messageboard with advertisement?
I'm not a lawyer, but as far as I know, No, you can not sue someone for spamming your guestbook.
So if you do not like people to spam your guestbook, you have to do something yourself
or if you like to spam other people's guestbook, you can freely do so.
have a nice weekend,
Las VegasOctober 6-8, 2015