If it can happen, it will happen, all you need is a sample (in this case: number of people who know about the time traveler) large enough.

There's a few reasons for that, including avoiding anachronisms for aesthetic purposes.

Time machines could be invented in the near future. In fact I am wholly unable to say one hasn't been invented already.

You may need to get an old usb stick from eBay. The good news is that they probably would be selling for quite cheap.

Unless they're priceless antiques of an age long gone and sell for millions of inflation and future currency exchange rate adjusted dollars

That’s a very good point.