Yesterday, the UK faced its worst terrorist attack in a long while. You don't need us to tell you how horrible it was.

Four were left dead, seven are still said to be critically injured, and a further 29 people have been treated in hospital.

It's a time to be sombre, resilient, mourn the loss of lives in yesterday's attack, and praise the emergency services for their response.

Donald Trump Jr has used it as an opportunity to be very very annoying.

Taking after his father

Unable to stay silent, Donald Trump Jr decided, only a few short hours after the attack, to tweet an article about a talk given by Sadiq Khan, without reading it, and quoting him entirely out of context.

You have to be kidding me?!: Terror attacks are part of living in big city, says London Mayor Sadiq Khan https://t.co/uSm2pwRTjO

— Donald Trump Jr. (@DonaldJTrumpJr) March 22, 2017

The article describes how London and Londoners need to be vigilant to attack.

“That means being vigilant, having a police force that is in touch with communities, it means the security services being ready, but it also means exchanging ideas and best practice.”

Headline is based on very first sentence, which if you'd bothered to read it could apply to any major city in the world. Key word: "threat" pic.twitter.com/u2S9WA7yoA

— Ciaran Jenkins (@C4Ciaran) March 22, 2017

Yes. Every major city makes preparations in case of a terror attack. Even Tokyo. It would be pretty dumb not to. https://t.co/I9reT0tMVC

— Ciaran Jenkins (@C4Ciaran) March 22, 2017

@DonaldJTrumpJr a "threat" is something you prepare against, like NYers and terror, Floridians and hurricanes, Californians and earthquakes

— Chris Choi (@thischoi) March 22, 2017

Sadiq Khan was not taking the defeatist attitude implied by Donald Trump, who many people think hadn't actually read the article.

The internet has been less than happy with Donald Jr's reaction.

@DonaldJTrumpJr Go fuck yourself. As a Londoner who lived through the IRA, anti gay nail bombings and 7/7, this is not the time to be cock.

— Tom Coates (@tomcoates) March 22, 2017

@DonaldJTrumpJr Khan is right. These things happen. We fight against them. But we don't wildly over-react or let them change our way of life

— Tom Coates (@tomcoates) March 22, 2017

@DonaldJTrumpJr And we absolutely don't choose to scapegoat whole communities to make ourselves feel better. Now shut the hell up.

— Tom Coates (@tomcoates) March 22, 2017

Oh absolutely do fuck off you worthless fuck. Don't even mention our country, ever. Everyone loathes you. https://t.co/FiiPALYd0L

— Sali Hughes (@salihughes) March 22, 2017

Is this helpful @DonaldJTrumpJr? Did you even read the article before goading London's Mayor during a live incident?https://t.co/Sm68UOcJQG

— Ciaran Jenkins (@C4Ciaran) March 22, 2017

@DonaldJTrumpJr don't you have another obnoxious canned trophy hunt to participate in w/ your equally-detestable brother? pic.twitter.com/HbU2xxjyRm

— Joe Papp (@joepabike) March 22, 2017

@DonaldJTrumpJr even if you werent disingenuously paraphrasing @SadiqKhan out-of-context youre still obnoxious for killing elephants for fun pic.twitter.com/ciAfbpA5Xv

— Joe Papp (@joepabike) March 22, 2017

MPs didn't mince words either, and called him a disgrace.

@DonaldJTrumpJr You use a terrorist attack on our city to attack London's Mayor for your own political gain. You're a disgrace.

— Wes Streeting MP (@wesstreeting) March 22, 2017

@janeswiftweir @DonaldJTrumpJr Jane, I've lived in this city my whole life. We have always experienced and withstood terror.

— Wes Streeting MP (@wesstreeting) March 22, 2017

People warned him to delete it before it's too late.

@DonaldJTrumpJr Seriously, delete this nonsense before it gets you into a world of trouble, you fucking idiot.

— Mike P Williams (@Mike_P_Williams) March 22, 2017

But it probably is too late, as half of the internet have been calling him out on his bullshit.

Many were annoyed that he'd implied Sadiq had made that statement yesterday, during the attack.

How dare you @DonaldJTrumpJr you take an article from @MayorofLondon from a year ago and do this at a time like this. #London

— Yasmin Khatun Dewan (@Yasm1nK) March 22, 2017

@DonaldJTrumpJr how DARE you post this as if he said it today.

— Marie Donn (@Marie_Donn) March 22, 2017

For the record, here is the Mayor's actual reaction to yesterday's events.

Londoners will never be cowed by terrorism. pic.twitter.com/SidIuIztvu

— Mayor of London (@MayorofLondon) March 22, 2017

And if you think it doesn't matter how Donald Trump Jr portrays Sadiq Khan, here is the reaction from people who like him, who took his tweet at face value without reading the article for themselves.

Just complete garbage from London's Mayor... a complete #ZERO https://t.co/mw3hd8Nv48

— US Army NC (@JTI_NC) March 22, 2017

I was shocked London had a Muslim mayor, and then I remembered that we used to have a Muslim president. #ByeBarry #PrayForLondonِ https://t.co/4SEtVZCQVa

— Jess Sayin' (@JessistheBest04) March 22, 2017

😁😁😁😁😁, a one-time admirer of world trade centre bombers ,now a Mayor of London confirms that terrorist attack in London today is normal https://t.co/juCla1fjJL

— Abuchi (@sam_ezeh) March 22, 2017

Although fortunately the majority of the reaction has been...

oh fuck off https://t.co/kjEDCsaicP

— Rachel (@underthenettle) March 22, 2017