Despite that fact that it is a magnificent day here (as it has been for the last week!), I'll share...
I was taxing my 150 around the outer taxiway at Toronto International Airport [old] Terminal 1, with all the appropriate clearances etc. (It was back in the day when 150's were still welcomed at YYZ - shows how old I am!).
As I taxiied a few hundered feet behind an Air Canada 767 parked in a "south hold" spot (not at a gate), I was suddenly up on one wheel, being blown off the taxiway. How I managed to not flip over, or even scuff a wing tip, I have no idea! I got back on the pavement, and conveyed my surprised unhappiness to the ground controller. He had seen what happened anyway, judging by the tone of his voice.
You guessed it, the maintenance crew were running one of the 767's engines at full power for whatever reason. Doing this requires a clearance, which they did not have. I'm sure there was trouble, but I never heard. Unfortunately, incidents like that, were one more nail in the coffin of "little plane should not be at big airports".
Now, when I taxi behind a large aircraft, I look at the grass (snow) behind it for signs of power being developed, if I think an engine could be running.