I guess I know the answer clearly when you put a comment on this picture! You leave a trail by means of a comment! :o)
Nowadays who will not leave a trail on internet?
You will even be surprised on the result when people reconstruct the story from your trails on the web. The story is totally different from your real life!!
Don’t think that the trail on snow will go away. When it was taken by a photographer and posted to web, it will be stored and contained in the digital memory for a long time! :o)
Our snow flurries on the ground will go away soon since rain is coming to Vancouver.
This is foot trails in my neighbourhood taken with my Fuji X10.