I’ve seen that some users are uploading traces that are substantially inaccurate, as the one we see here:
Based on my research on the forum, it’s not possible to request the deletion of a trace, is this still the case?
If so, is there the possibility to find the owner of the trace, to kindly ask him to remove it?
Details about the object: OpenStreetMap
You can use the OSM API for GPS Traces, the gpx file has the ID of the user who uploaded the trace.
I guess you’re looking for the author of the curls, the URL points to the bbox above the curls. There is no user and from what you can see in the screenshot, the WPs cannot be followed. I assume the author is someone concerned about their privacy and marked the track as private.
There are several curls in that area, unlikely to be from a person walking; possibly a helicopter or drone recorded the track.
The following image shows a flight path of a crop duster.
They’re in the OSM GPS tiles, so they would have been public at the time that they were uploaded. They’re not public now (just GPS points) so the person who uploaded them likely changed visibility. There’s no way for the GPS tiles to know when a trace has changed visibility, and it’d be technically complicated to “modify the layer to delete a trace”, so the GPS tiles don’t get updated when that happens.
The upload date (in the trackpoints of the download above, and visible in JOSM) is 2015-05-28. You could maybe have a look and see if anyone did any mapping in the area based on drone / helicopter imagery shortly after that date and ask them 
