Whenever I use the touch pad to scroll with two fingers, some lines of text in the current window are copy-pasted. This happens very rarely (maybe once a week).
I am certain that this is not caused by interaction with the context menu (which provides a copy paste option) because I never see a context window and the mouse cursor had to move very quickly to not notice a quickly disappearing window. Moreover, when I switch to a text box after this happens, the clipboard is still the same as before.
The reason I am blaming the touch pad (driver?) is that I only ever saw the issue when using the touch pad.
I am using Fedora 27 on a P51 Lenovo Think Pad.