A few Mac OS versions ago. I think it was Mavrix, I couldn't play my purchased iTunes movies on the Intel Macs for some apparently obscure reason. Scanning various answers provided by Mr Google, I began to suspect the DisplayLink USB graphics drivers. After locating the saved installer .dmg file, I uninstalled the drivers & my problem went away, along with it the ability to connect an external display via USB.
Earlier today, I thought I'd check whether there was an update to the DisplayLink drivers to suit Sierra. There were. Downloaded & installed, works fine.
My Intel Macs either lack Thunderbolt completely or have only one T/bolt port, so if I have that port in use with an ext HD, I can also use an external display. My T/bolt SSD/HD adaptor doesn't allow daisy-chaining as it has just one T/bolt port.

I had a tiny metal splinter removed from my right thumb 25 hours ago. I watched the whole process intently which is NOT something I do at blood-letting time.

// @skematica

When playing videos in Safari with Sierra as the OS, Vimeo videos will show a Picture-inPicture control once the playback is initiated.

Not so with other sources such as YouTube. In these cases, do a double right-click. That is, a right-click on the video itself, ignore any dialogue boxes then right-click again. If PiP is available, it'll be shown in a new dialogue box.

Have fun.

Almost the same here, I pretty much just use Flickr, although there's a mostly-dormant Tumblr account as well.

// @japchap

Thumb is pretty sore when I put pressure on it. Fair enough, I guess: they'd been poking around at it with a set of tweezers & the sharp bits of a fat syringe needle.

Seems like they do! It's a curiosity thing.

"Booby-trapped" USB drives have been appearing in peoples' letterboxes around theses parts lately. http://www.itnews.com.au/news/crims-place-booby-trapped-usb-drives-in-letter-boxes-437969

Back from the ER. A sliver of metal was extracted, there may or may not be more in there. The general area is not so sore to touch, just where they cut thru a few layers of skin to get at it.
I need to soak it in hot salty water for 15 minutes to see of anything more comes out.

Almost 6am. I'm off to the ER at hospital. There's a steel or wooden splinter in my right thumb that's starting to get swell up & get painful to the touch.

Updated my Yahoo password.