If no one has seen or measured them move surly its possible and more likely they haven't moved they just appear to have moved. To me it seems likely that The trail is made from the fact the rock simply blocks the wind and in certain weather conditions this makes what looks like a trail from a moving rock ?

It would be easy to set up a time laps camera to see if in fact the rocks move , and if they do move then you could simply placea bunch of camara and mesuring devivces near rocks and place some artificail rocks down to see which ones move the best and in what conditoins.

you could evan have fake rocks with giroes and petentoimiters in them that update wirelesslesy in reel time.

not realy a hard thing to test could be tested and worked out for under $800 and im sure u could raiz that money easily.

5/5ths of this move rocked the monkey's bollocks! (that is; was extremely satisfying)
I love how Al Gore goes into the Achilles Vent to destroy the death star.