The Stop Enabling Sex Traffickers Act (SESTA) and the Fight Online Sex Trafficking Act (FOSTA) has tremendous consequences for webmasters who own a website with an adult content. Two bills directly target US webmasters.

Website owners are now responsible for the content published by their website users.
(Sec. 2) This bill expresses the sense of Congress that section 230 of the Communications Act of 1934 was not intended to provide legal protection to websites that unlawfully promote and facilitate prostitution and websites that facilitate traffickers in advertising the sale of unlawful sex acts with sex trafficking victims. Section 230 limits the legal liability of interactive computer service providers or users for content they publish that was created by others.
The law states that webmasters who own a website with user-generated content
(Sec. 3) The bill amends the federal criminal code to add a new section that imposes penalties—a fine, a prison term of up to 10 years, or both—on a person who, using a facility or means of interstate or foreign commerce, owns, manages, or operates an interactive computer service (or attempts or conspires to do so) to promote or facilitate the prostitution of another person.
For example, you own a social media website. Someone publishes a sex ad. you are then legally responsible for the sex ad being on your website even if you didn’t publish it.
If a webmaster’s website counts 5+ posts of people selling sexual services, he will be sentenced to up to 25 years imprisonment.
A website user may claim the webmaster indemnities to take advantage of the situation:
A person injured by an aggravated offense may recover damages and attorneys’ fees in a federal civil action.
The new SESTA-FOSTA bills reduce the freedom of webmasters who own adult websites. This means that they should moderate forums, classified ad websites, comment area like never before. On a large website with many pages, it is easy to let 5 sex ads go through when there are thousands of comments and may be when the moderation job is outsourced in another country.
The expression “facilitating prostitution” is really vague. how a judge would determine what could facilitate prostitution. Could it be a half naked picture with a phone number and a sentence like “I am hot today, call me tonight at 888-4444-4444.”? I don’t think so.
Backpage.com was accused of facilitating prostitution. This means that the US authorities have found post ads on the backpage.com website where people obviously sold sexual services. On top of the bad personal consequences related to the legal proceedings, when the US law enforcement authorities decide to take down a website, they seize the domain name and the web server. It means that everything is lost in a blink of an eye without notice.
Discussion boards, classified ad websites, social medias, blogs with comments are now at risk. don’t forget that the .com, .org, .net and many other domain TLDs fall under the US jurisdiction. It would be better to consider a domain TLD like a .ONL from a European registry company.
Envisage hosting a website in Europe. Anyways, it is always possible to use a Content distribution network (CDN) like Cloudflare.