Today in celebrity gossip: Justin Bieber promotes his new selfie app the best way he can, a knife-wielding bum threatened to murder morning show host Michael Strahan, and Harry Styles is not going solo quite yet.

It's not easy starting a selfie app to compete with Instagram, Twitter, Facebook, and basically every other single social media platform, especially when you're also trying to balance a singing career with hot boxing and the acquisition of terrible tattoos. Yet multi-tasking wunderkind Justin Bieber has just taught a master class in publicity generation by posting an allegedly nude selfie to his Shots profile. Here you go:

As you can see, Justin Bieber is clearly nude from the waist up. In Victorian era terms, this is as naked as it gets. In present day IRL terms, Justin Bieber pretty much just has his shirt off after doing a bunch of push-ups and everyone's titillated I guess. But the most important thing to remember is that Shots is a thing that exists and in that respect Justin Bieber has done his job. There you have it. There I have it. There we all have it. Case closed. [Page Six]

If you happen to be a knife-wielding bum, please stay away from Michael Strahan for the time being, as you have spooked him good this day. According to Page Six, the co-host of Live! with Kelly and Michael was indirectly threatened by a man outside of ABC Studios' Times Square location when the man pulled a knife on a security guard and claimed he wanted to "kill Michael Strahan." As you will recall if you were the knife-wielding bum in question, a police officer slapped the blade directly out of the bum's hand before he could actually do anything violent, and all the audience members lined up outside for that show's taping remained mostly blissfully ignorant of the incident. But you know who did not appreciate being threatened with murder by a knife-wielding bum? Michael Strahan. He found out later that day what had happened and was not a fan. Not at a fan at all. I usually try not to editorialize too much here, but please, knife-wielding bums: Put that knife down. Thank you. [Page Six]

Harry Styles is not leaving One Direction to go solo yet, okay? He's not. Like any boy band or girl group with a particularly famous frontperson, rumors will always swirl that that person is itching to go solo. So it went with Beyoncé and Justin Timberlake for years before they went solo, and so it currently goes with Harry Styles. The newest round of speculation was sparked by comments from Kodaline singer Steve Garrigan that he'd been helping Styles write music for some kind of side project, but he didn't give exact details about what the project might be. "It could be on his album if he does something, but I don't know. Nothing is set in stone." See? He doesn't know and nothing is set in stone. Furthermore, One Direction's notoriously iron-fisted management denied any and all solo career aspirations on Styles' part: "There are no plans for Harry to release any solo music at this time, any writing that he is doing is for potential One Direction songs." Which is music industry speak for Harry Styles will only release solo material when One Direction sales have begun to flag and/or market research says that fans would be okay with it after priming them with well-placed pieces of gossip hinting at the possibility. And as we all know, that won't happen for months or even a year, so relax. [E! Online]

The new trend in celebrity rehab is to go to rehab in secret and then own up to it only after you've ostensibly gotten yourself back on track. Zac Efron and Selena Gomez have both gone that route, and joining them now is Mrs. DeGeneres herself, Portia de Rossi. According to InTouch (via Page Six), the Scream 2 star checked into rehab for the month of May at the Passages Malibu luxury rehab hotel. Ellen DeGeneres apparently visited every weekend, and though it's unclear for what malady de Rossi sought treatment, it should be noted that Passages deals with substance abuse only (as opposed to eating disorders, for which de Rossi sought treatment back in 2000.) So how is de Rossi doing now that she's out of rehab? Unclear! Neither InTouch nor Page Six have much to say about that. But while we're irresponsibly speculating about peoples' lives, maybe let's try a positive speculation on for size? Portia de Rossi is doing great! [Page Six]

Meanwhile funnyman Robin Williams is back in rehab as well. TMZ reports that he's checked himself into the Hazelden Addiction Treatment Center in Lindstrom, Minnesota in order to "fine tune" and "reaffirm his commitment" to sobriety. Which, what does that even mean? Has he fallen off the wagon or hasn't he? If his representatives are actually trying to tell us with a straight face that Robin Williams went to rehab just for old time's sake, then that is insane. Or is it? I know addiction is a complicated situation and unique to all who suffer it, but still. Preventative rehab? Have you ever heard of such a thing? Is that the new euphemism? Is it like going to rehab for "exhaustion"? Well, whatever's going on, get well soon, Robin Williams. Your iPad commercials make me cry every time, true story. [Page Six]

Meanwhile, Katy Perry fell down and struck a pose:

Here's Mariah Carey looking totally normal while walking her dog:

Here's Austin Mahone doing whatever:

And guess who's south of the border again. Kellan Lutz obviously!!