A video that goes viral is the holy grail of social media marketing. But the content of most videos produced to promote restaurants just isn’t wacky enough to make the online audience want to share them with friends. So why not get into the game this way: leverage viral videos from others to gain attention for your concept or brand.

That’s what Boston-based Legal Sea Foods (LSF) and its longtime ad agency DeVito/Verdi have done in the chain’s latest ad campaign. The format for LSF’s new TV ads is simple: show a quick YouTube clip of people doing dumb things, then deliver the ad’s two-part message: ‘Fish is brain food. We have fish.”

But the dumb things LSF chose to feature in its content—all of them routine to those who send and receive viral videos—are groundbreaking from a restaurant advertising point of view. In this context, the clips make the LSF ads eye-catching…or, in a couple of instances, make viewers avert their eyes from the screen. Either way, the ads are built around exactly the kind of videos that people swap over the Internet millions of times each day.

Legal Sea Foods is a classy, well-known brand that operates 32 polished casual dining restaurants in big cities up and down the East Coast. Yet its new ads depict the same level of ineptness and stupidity, and resulting level of physical harm, as is typically on display in “Jackass” movies or on any episode of Comedy Central’s highly rated “Tosh.0.”

A couple of the video clips used by LSF are relatively harmless. The girl who climbs into a commercial-sized laundromat dryer and goes for a spin will probably be okay when it’s over. And it’s likely the teenager who takes a direct hit from a Roman candle fireball was able to walk away at the end of the video sequence without going to the emergency room.

But other clips, while definite attention-grabbers, are a little unsettling. One that shows a college-aged boy attempting to stop a rotating ceiling fan with his head might upset some viewers. And the gruesome video of a boy getting his tongue stuck to a frozen metal pole might come off as cringeworthy for many, many viewers.

The clips are authentic, and LSF and DeVito/Verdi present them in their original Web-resolution formats—grainy cell phone video, shaky handheld shots from GoPro-type cams.

You can bet these ads will be shared all over the social media universe just as soon as they start to run on TV. But will it help Legal Sea Foods attract more patrons? Our guess is that these ads will generate plenty of buzz around the brand, especially among the young demographic for whom viral videos are a part of life.

So could other restaurants do something similar to promote their brand? Why not?