This isn't the real world; it's an Internet forum and we go by the rules that have been set out before us.
That is ridiculous.
What I suggest is that people start suing the forum if they realize a loss due to some of the activities here.
How it works is that you sue the whois privacy service (which is in Panama). It is unlikely that company will provide a court defense over a service that costs a couple dollars a year. Most likely they will either divulge the true registrant or simply default.
If the true registrant is identified they will need to provide a defense and identify themselves or they will default. If they identify themselves then you can start identifying the staff and calling them in for depositions. If they default then you can probably get a court order to seize the domain from the .org registrar which is located in the USA. If bicointalk.org were to default you really don't need that solid of a case, you just need a prima fascia case which will be successful if they default. By suing the forum you will put them between a rock and a hard place.
If you think this forum does not matter in the real word, think again. The Chairman of the Bitcoin Foundation shot himself in the foot by posting here and Barry Silbert used it against him in court Vessenes has not posted here since:
http://cointext.com/wp-content/uploads/2013/11/alydiancomplaint.pdfhttps://bitcointalk.org/index.php?topic=306672.msg3289385#msg3289385Forum posts have also been cited in a several other criminal and civil cases such as the Silk Road and pirateat40 prosecutions.
Actually the forum would be protected by Section 230 of the
Communications Decency Act which basically says that a website with user submitted information (posts) is not considered to be the publisher of such information.
The person who actually posts information (posts a post) is liable (when liability is appropriate) for anything they publish (post).
That depends of the specific facts. That immunity goes out the Window if the web site conspires with people who post or place the ads. it also does not provide immunity from criminal liability. Giving Trade Fortress specialized privileges to promote a fake bank covers both those issues. You should read the link you posted so you understand what it means. Some case decisions are posted there.
As I have explained any defenses won't matter unless Mr. Marquardt (Theymos) shows up in court.
Theymos would need to be properly served in order for him to have to show up in court. Otherwise any judgement against him would not be enforceable, and would be reversed.
If you were referring to TF posting in the VIP section then that is not something that only he was allowed to do. Anyone else is allowed to post in the VIP section provided they donate at least 50
BTC to the forum (that much was worth much less when TF donated and when most people were donating).
A case close to one regarding advertisements is Goddard v. Google, Inc.
Immunity upheld against claims of fraud and money laundering. Google was not responsible for misleading advertising created by third parties who bought space on Google's pages. The court found the creative pleading of money laundering did not cause the case to fall into the crime exception to Section 230 immunity.