Forums are ridiculously difficult to get shut down. Since they are made up entirely of individuals whose opinion are protected by free speech laws, law enforcement agencies would need to prove that the forum is set up with the intent of illegal actions.
You will notice at the bottom of each page is a link to "Dmca Takedowns" where if someone as a complaint about material they can file a notice. If the site owner ignores these requests, it can be shut down but so long as the purpose of the sites isn't based on posting copywritten content and they react in a timely fashion, the site could not be legally shut down.
That said, in other areas, companies have filed complaints then used law enforcement to seize a website at the source, ie. hosting. Without the site owner's immediate knowledge and consent. There they would have access to all the information.
I have wondered if the switch from JWD to JWN was motivated due to legal pressure. Most people don't know, but .com stands for "company" or "commercial" or business/websites focused on selling or marketing a product. Since there is revenue generated from advertisements, there could be a slight legal argument that Simon is not just providing a forum for discussion, but runs a company that benefits financially on the discussion and opposition of the Watchtower. Slight, but still present. Changing to .net (network) classifies it as a network for discussion. You may note that www.watchtower.com redirects to jw.org.
In the end, I have seen some websites set up fight certian causes or on shady legal standing where large corporations have stepped in and hit the owners with massive legal suits. In each of these cases the site owners have complied and handed over private information. I would not fault Simon for doing the same either. It is great to have a place to discuss and share ideas, but I would not ask Simon to spend tens of thousands of dollars on legal fees or be ruined financially with a judgement in the hundreds of thousands of dollars to protect my account details.
This site doesn't really request much personal information, so it is unlikely to be a target. If you are concerned over your privacy or feel you may be a target, don't use your real name, have a thowaway email address to sign up. Sign up for an internet proxy so that your IP cannot be traced back to your internet hosting provider.
As to the point asking if the WT monitors this site, I recall seeing a webmaster from either here or another similar forum posting an IP from Bethel confirming they do check these sites out. When I was in my late teens and visited bethel I actually asked the guide about apostate books and he said that they did have a department of 2-3 brothers that "skimmed" apostate litterature (this was before the internet was popular) He said that they would select spiritually strong brothers and also rotate them out. I asked a couple follow up questions but he got abrupt with me and said that wasn't the focus of the tour and wanted to highlight the blessings of Jehovah's work instead. My mom hauled me off and scolded me for asking questions, I think moreso to show that she was a fine Witness rather than concern for me.