Some of China’s leading facial-recognition players, for example, are now moving into gait recognition. Hanwang Technology was an early entrant in the field: it was forced to rethink its fingerprint-recognition technology when the Sars epidemic of 2005 left people in China terrified of physical contact. “We can see the human figure and his gait, so if his cap is pulled down [we] can still recognise him,” explains Liu Changping, president of the Beijing-based company.

— Inside China’s Surveillance State (Financial Times link via Tyler Cowen)  

Immediately I remembered two passages, both of which featured altered gaits to escape detection.

The less well-known first:

She waved him to silence. “We will be doing an imitation as we walk,” she said. “We will walk one behind the other down the gutter in the middle of the street, our footsteps combining into one of these rhythms, like two hands on the keys of a piano; later I will show you how a single person walking can do this nearly as well.”

“We will be doing an imitation of ‘nothing right here,’ you see?”

— Declare (Goodreads link )¹, Tim Powers  

Elena and Andrew are hiding from something in the sky, watching them as they flee across Paris during the lead-up to World War II. Declare is one of my favorite books and Tim Powers one of my favorite authors. Many of his books take historical events that are a bit odd and reframe them into supernatural events.

And the other:

And if we crossed there making only natural sounds, the kind that don’t attract the worms. . . .

“We must walk without rhythm,” Paul said and he called up memory of men walking the sand . . . both prescient memory and real memory.

— Dune (Goodreads link ), Frank Herbert  

One can now be surveilled by their gait – someone is always watching. Much like dazzle camouflage an unfamiliar gait makes it difficult to estimate movement and identity. Nothing right here. So step lightly and naturally and to a new rhythm.

You will know them by their steps.

— Matthew 7:16 (modified)