Yes, they can sue you and as it is a civil action, if you aren't in the country, you will have to go their in your defense or forfeit the case, just like in the US.
As for proper action to take, stop posting the public content and file a legitimate claim with the bbb and ftc, as they are both international and don't take scam claims lightly.
If you keep hosting and posting, you are going to become the one that the law comes after, as they have clearly filed a ' cease and desist ' request against you with your hosting company and under international consumer privacy laws, as well as laws of false persecution, which are posting ' liable ' claims of hear-say situations against another part for public judgement is against most countries rights to a fair trial. Hense why cease and desists letters are taken VERY seriously.
If you continue to post the content in question, and most of whatever action they are taking against you is pushed, you could end up on the wrong side of this, as a risk to the company's livelyhood, which is a ' depervation of trade ' and ' dafamation of character '...which again, outside of an official legal claim, can be disputed.
If you continue that line of action, you could eventually have a restraining order put against you, which in this case, would be filed as a gag order to prevent you from publically speaking about the company in question or face immediate legal action. It sounds far fetched, I know but it does happen.
A lady in the UK filed such a claim against a man in Germany due to his posting how great she was in bed on his facebook account and she never made the weekend date he bragged about due to calling it off after being sick in the hospital. There are countless cases of these actions flipping.
Beware and file the claim legitimately with the proper authorities so that they can monitor the situation and complaints through their investigation process. It may take a while for the company to get what they deserve, if found guilty but it will happen if they are.
Do the right thing and get yourself out of that drama so that it doesn't come back on you with a simple little side step you or the other party make in the wrong/right direction.
Best of luck with it.
I published an negative review about free trial scam diet product (UK company) My site was previously hosted with a UK server provider. But the "con" hired lawyer to send legal notice to hosting comany. So I received abuse report from my host and so I moved my site to American host.
But after a week con's lawyer sent notice to my American host too!
The alleged company is a proven free trial scammer. There are 1000's of complaints floating on the internet.
Now I want to know where can I host these type of content. I'd prefer an American host; fine with any other suggestions and recommendations.
One more question.
Can a UK company file a legal suit against American company at London high court? Is it valid?