Justin Timberlake Digs at Britney Spears in Concert

During a recent tour stop in Zurich, Switzerland, Justin Timberlake busted out a cover of the Amy Winehouse hit, "Rehab," which is a cool track.

But what makes this noteworthy is that instead of the original lyrics - "They tried to make me go to rehab, and I said no, no no" - Justin threw his own variation in and sang "They tried to make her go to rehab, and she said no, no, no!"

Hmm. Wonder who he's talking about. Britney Spears, maybe? Just a guess. One that you don't need to own a celebrity gossip site to come up with.

Here's a clip of Justin Timberlake covering "Rehab" ...

Not unfunny. As if it weren't obvious enough, later in the show, Justin Timberlake pulled a similar stunt with a cover of Gnarls Barkley's "Crazy."

Unlike Akon, he didn't throw anyone off the stage - but Justin struck a chord with more slightly altered, possibly Britney Spears-bashing lyrics.

Once again, he changed the words from first person to "I think she's crazy... I think she's crazy..." and "I remember when... I remember when she lost her mind."

So do we. It was February. Enraged and bald, Britney went all "crazy" and attacked paparazzi with an umbrella, while stopping at a convenience store on her way to rehab for the third or fourth time. It was awesome.

One can only hope JT protege Esmee Denters doesn't follow Spears' path to destruction and ridicule. Click HERE to see a clip of Justin goin' "Crazy" on Brit!