There's a rather annoying bug in the synaptics driver on Linux on the Dell XPS 15 9550. Basically, if you are using one finger to move around and another to click the "button" areas at the bottom of the screen, instead of taking that second finger as "click here", it sometimes interprets the second finger coming down a moment after the first finger raises (having finished positioning) as "oh, that finger just jumped to the bottom of the touchpad" and moves the cursor to the bottom of the screen, converting the click on a button (or whatever) into a click on something in the task-bar. It doesn't kill you, but it is *so* bloody frustrating to have apps launched or switched and break your concentration.

I haven't found a good way in KDE to set a "humans can't move that fast" threshold for this. Synaptics seems to have a "JumpyCursorThreshold" but looking at the code it doesn't seem like it would actually avoid this bug on multi-touch trackpads, and the feature isn't exposed in KDE's control panel AFAICS.