>Given: Some graffiti is on the wall. >Question: who is `responsible' or `liable' for graffiti? This question already has a known answer. The author of the words is the one that is liable for them. No other parties are liable unless they had prior knowledge; this would make them conspirators. However, under certain circumstances the owner of a facility can be held liable for not removing libelous graffiti. I picked up a paper from the net some time back (/telecom-archives/sysops.libel.liability on ftp.lcs.mit.edu, ``Defamation Liability of Computerized BBS Operators & Problems of Proof'', by John R. Kahn) which discusses that point. The judgement is context-dependent -- one court noted that different standards apply to a New York subway car [sic] than to the interior of a manufacturing plant -- but the general rule is that if you know of some defamatory graffiti on your property, you're obligated to remove it.