Decidedly, the world has changed, but the question is, "Have the grandees who run Big Sport taken notice?"
Yes, it is simplistic to bracket these three manifestations of frustration and rage together.
The Istanbul protesters seemed indifferent to, or even mildly positive about, their city's prospects of hosting the 2020 Olympics – although they have thrown a spanner in that particular works.
The London march was an internal sporting affair devoid of broader political ramifications.
The demonstrators in Brazil certainly are questioning the money lavished on new stadia, although even here, the Confederations Cup seems to some extent to be a convenient focal point, rather than a fundamental grievance.
The point though, I think, is this: After four or five years of widespread financial and economic turbulence, people are finding it tough to make ends meet, even in comparatively fast-growing economies, and this is making them grumpy.
But while the people's wallets have been getting thinner and their mood darkening, Big Sport has been floating along, largely unaffected, in its bubble economy, buoyed by copious quantities of television and sponsorship dollars.
Protected – but also cut off – inside this comforting cocoon, I have seen precious few signs to date that the men in charge of the world's biggest sports events have taken these changed attitudes to heart.
FIFA President – and International Olympic Committee (IOC) member – Joseph Blatter's comment that people should not use football to make their demands heard suggests strongly that he has yet to join up the dots.
So let me state it clearly for them: lavish sporting projects are no longer – for now – in keeping with the mood of the times.
What is needed is restraint. Allied with explanation.
There were signs in the June 10 conference call given by Aldo Rebelo, the Brazilian Sports Minister, that the political classes – with more of a vested interest in staying attuned to the public mood – are taking the warning signs on board.
Questioned about the cost of stadiums, high ticket prices and the "elitization" of football, Rebelo acknowledged that the price of World Cup tickets is "way beyond the means of many of our poorer citizens" and that "we do worry that the elitization of soccer in Brazil may happen".
Something else: there have been suggestions that the scale of the protests in both Istanbul and Brazil was in reaction, partly, to strong police measures against initial demonstrators.
One of the most important things prospective hosts of sporting mega-events need to demonstrate, of course, is cast-iron security protection.
It would be only natural if the new wave of prospective mega-event hosts, including both Brazil and Turkey, felt the pressure to prove their capabilities in this regard particularly keenly.
In the present mood, however, there is a high risk that enhanced security may antagonise the very people on whose support Big Sport is dependent to validate its rather decadent corner of the human cultural edifice when times, for many, are tough.
It is a delicate balance to strike, but, once again, restraint and explanation would go a long way to easing inevitable tensions.
Those of us who chronicle Big Sport know in our bones that staging an event can do a host city or country and most of its inhabitants a power of good.
In many ways, the most glaring failure of explanation has been that the case has rarely been really convincingly articulated by sports authorities.
This is, in part, because some of the benefits are difficult to measure.
But it is also the case that over the past couple of decades, while the great cities of the world have been queuing up to boost their prestige by getting their hands on high-profile events, the panjandrums of sport have barely had to worry about such niceties as self justification.
The events of recent weeks – and the forthcoming referenda on possible 2022 Winter Olympic bids in the highly prosperous European cities of Oslo and Munich – should jolt them into turning their attention urgently to composing a compelling answer to the question: What's in it for us, the inhabitants of the hosting entity?
Otherwise, they may find themselves a lot less spoilt for choice than in recent times when selecting the amphitheatres for their precious events.
What would have been a most desirable bid for the 2022 Winter Games by St Moritz/Davos has already been scrapped after Swiss voters declined to approve funding in a referendum.
The mirror image of the sort of message I have in mind is on YouTube, loud and proud, where it has been viewed more than 2 million times.
It is a passionate, but reasoned anti-World Cup/Olympics polemic featuring a young woman called Carla Dauden.
It is simple, it is effective and it gives a voice to those perplexed that their Government should be spending heavily on sports competitions when peoples' day-to-day needs frequently go unmet.
"We do not need stadiums, we need education," she says.
"We do not need Brazil to look better for the world, we need our people to have food and health."
You get the idea.
You can find it here.
I heartily recommend that decision-makers in the sports events world devote six minutes of their time to watching it.
And that they then turn their minds to producing an equally simple, equally compelling response, explaining – with due humility – how their cherished sporting properties can and will in future increase the supplies of food, education, health and happiness to ordinary people.
The nightmare scenario for Big Sport is that it becomes a focal point for broad-based, international protest in the way that global Governmental/business gatherings such as the G8 and Davos became, and to a degree still are.
We are a long way from that.
But it is high time that the stewards of the world's great sporting festivals shook off the air of complacency that the good times have engendered and set about justifying their existence to the ordinary, hard-pressed, men and women who have to live outside the bubble.
David Owen worked for 20 years for the Financial Times in the United States, Canada, France and the UK. He ended his FT career as sports editor after the 2006 World Cup and is now freelancing, including covering the 2008 Beijing Olympics, the 2010 World Cup and London 2012. Owen's Twitter feed can be accessed here.