First of all: myStromer AG has contacted all affected owners personally.
For those who are not familiar with the ST5: This bike has a unique construction. Stem and handlebars are one piece. You'll found a bunch of pictures in the ST5 section of this forum. You'll also found further and more detailed information on the
Swiss stromerforum. This is in german and translation might sometimes misleading. AFAIK, the issue came up among a routine check at a dealer - and until now, all checked equipment passed the test. From my point of view, the ST5 is safe. I'm riding a checked ST5 at the time and i do it with full speed - as it should be done with such a bike.