[loceng]

So what source do we trust on the numbers?

Satellite imagery is likely the best way to estimate.

The massive crowds in slow march peaceful protest videos I saw were astonishing.

However if we extrapolate that not everyone who'd support it or are silently supporting it - what % of people available to protest/march were out?

Edit to add: downvoting a question asking for trustworthy, quantifiable sources - you're failing.