When demonstrators took to the streets to protest the death of George Floyd under the knee of a Minneapolis police officer, the cause was just but the worry was real: Were the marches going to lead to massive new outbreaks of coronavirus just as most of the United States had flattened the curve?
At the same time, newly reopened restaurants and stores drew customers – sometimes masked, often not – while crowds returned to beaches. 
Released from sheltering in place, people held gatherings at their homes, trusting that the folks they invited would be careful not to expose everyone around them to danger.
Now, cases are surging in Texas, Florida, Arizona, Nevada, West Virginia, Tennessee and Montana; average case counts hit new highs on Sunday in a dozen states, California included. For 27 straight days, the count for the country as a whole has climbed relentlessly higher.
So who’s to blame for the frightening increase in infections? Because the new coronavirus is, well, new, there’s still a lot one doesn’t know about what makes a situation safe instead of a potential Covid-19 hot spot. But tentative answers are coming in now, sometimes at great human cost.
The protests don’t seem to have caused any major health problems, even though the participants often were in close proximity and were frequently yelling, which increases the exhalation of droplets. Demonstrators in Boston were no more likely to test positive afterwards than the city’s population as a whole. The rates of positive tests were similarly low among demonstrators in Minneapolis and Seattle. A national study by the National Bureau of Economic Research found that overall, coronavirus rates were no higher in counties that were the sites of large protests than those that saw no demonstrations.
These findings are far from definitive, however. In Los Angeles, demonstrators had trouble getting testing appointments, which could mean that some cases are unknown and uncounted; in New York City, city officials instructed contact tracers not to ask people who tested positive whether they had attended protests, as though ignorance was going to make people safer.
Massive gatherings still aren’t a good idea – some protesters did in fact become infected – but there’s no indication so far that the protests were super-spreader events. Being outdoors almost certainly helped.
Instead, the most common sources of recent Covid-19 surges have been some of the smallest venues, especially eateries. People there are socialising indoors, often in close proximity, talking loudly to be heard over the chatter, their masks coming off as they eat or not worn at all. The long-awaited reopening of indoor restaurants also appears to be a contributor. 
Private get-togethers are repeatedly cited by health officials as problematic. Contact tracing in Sacramento found that the biggest sources of recent spread there were graduation parties, funeral gatherings and the like. Caution falls away when people are with those who are known, loved and trusted.
It would be premature to draw too many lessons from the limited data one has at this point. Still, the lectures given by public health officials appear to have been borne out in key ways. Outdoors is clearly less risky than indoors. Social distancing is needed, as are masks, masks, masks. Covid-19 is apolitical and without judgment; it neither rewards protesters nor punishes people who want some company. It just follows the laws of science.