What i want to know is... what makes them think a single british person has enough firepower to literally blow up a country. And why do they have to dig up marilyn monroe before blowing up the country?!

Good Lord. Of course, as others have mentioned, the only thing more disturbing about this is how the DHS actually knew it was him.

Echelon indeed...

Now that I think about it, it's sort of appropriate that GOG released Deus Ex when it did. Looks like we'll be seeing UNATCO sooner than we think...

And in this moment, Geore orwell wins hand down.

They saw V for Vendetta and obviously got scared when they heard a brit was going to come and destroy America. It's quite normal for a police state.

I honestly believe there's more to this story than just this. My personal gut feeling is that it was the tweets coupled with something else (possibly an incorrectly filed or invalid visa waiver) that barred him from the country.

The story started a few days back from The Sun - all they knew was that they'd been kicked out of the country, The Sun found their tweets and tried to put two and two together on its own.

there are programs used to spy on social media, one of them is actually easy to acquire, its called radian6, you can use it to scan social medias for keywords such as your name and other things. This can be useful for companies who want to reach out for their customers or protect themselves from bad press and slander.

yeah. the biggest question is how did they know. do they have programs which scan the internet for name and after finding it on websites such as facebook, twitter, myspace etc. they run algorithms looking for questionable sentences words?

or was he just extremely unlucky and someone decided to actually read his tweet just cause?

seeing as it is not the first time, extreme low probability of simple random check USA government does scan the web collecting every possible information on it and flagging you if a program deems you dangerous.

Incorrect waiver is near impossible with most airlines here since they do it for you and you need the confirmation printout on you before you can board in many cases
Consider the guy put on the no fly list for a tweet he sent 4 weeks before his flight when the airport was on strike about how he's "blow them sky high if it stops (his) holiday" he also got fined 3grand for that tweet (Stephen Fry paid it for him and him and many others ReTweeted it for weeks whenever they were leaving the country).
The reason? The DHS reported it to the airport he was flying from IN THE UK!

So if i write here I will destroy america, they will not only check this, but also find my IP address and personal data?

Because most people use nicknames on twitter, not real names.

So one thing is finding that sentence, and the second is to pin it on a guy who is about to arrive to america...

A grand day for internet harassment.
Imagine you walk into an internet cafe or somesuch and find someone's Twitter/Facebook/something still signed in. Just write "I have a bomb in my pants and I'mma explode on Americaaah!" and they're suddenly banned from the US.

Also means that now there's some actually annoying use for hacked passwords.

Not especially. I've known people to be turned away because they couldn't prove they were going to leave the country within 90 days, which invalidated their visa waiver (I have somewhat personal experience of this - flying out to visit my fiancee whilst a K1 visa application was still being processed - I entered the country on a visa waiver to visit, and had to explicitly prove that I was intending to return to the UK, by presenting signed confirmation that I was still employed, still had bank accounts, a place to live, etc etc). Besides, it's just one of myriad possibilities.

Basically, there's too much information missing to make me wholly believe the story (though the fact it came from The Sun in the first instance should be enough alone). In everything I've read thus far, they mention being questioned about the tweets in the -second- interview, which makes me wonder what they were asked in the first. And the document they're displaying that mentions the tweets - it's only one page of a multi-page document. What's on the other pages?

The US deserve everything they get..... the fascism makes me sick.