The magazine which has published this is US citizen Samir Khan's one, in which he stated he was "proud" to be a traitor to US:
An online Al Qaeda magazine has released tips with images on planning terrorist attacks. The English language online magazine is believed to be led by American citizen Samir Khan, currently living in Yemen, according to CNN.

The violent article, titled "The Ultimate Mowing Machine," advises the use of pickup trucks to "mow down the enemies of Allah." It encourages the use of a four wheel drive truck, citing "the stronger the better."

"To achieve maximum carnage, you need to pick up as much speed as you can while still retaining good control of your vehicle in order to maximize your inertia and be able to strike as many people as possible in your first run," the article reads.

There are many other terror tactics in the magazine, including the use of firearms to shoot up a Washington, D.C. restaurant.

The site caught the eyes of counter terrorism officials because it is written in perfect English, including the correct us of colloquials.

"The concern is that this magazine will reach kids who have never really been very interested in violent jihad before," says a counter terrorism official who has been tracking Khan for years.

"The magazine seems to make it fun and accessible. It used to be to get into this you needed to speak Arabic. Now you don't — English subtitles, English translations of extremist videos, that's the norm now."

Source.