Google loves data. It has been one of the hottest topics over the past few years, with Google saying it is collecting data to make services better, while privacy advocates say it's unnecessary. Well, here's something good coming from location data: you can see the impact that social distancing measures are having. 

Many locations are on some form of lockdown aiming to prevent the spread of coronavirus, that might be staying home, shelter in place - whatever you want to call it. The aim is to reduce social contact and slow down the spread of the virus between people.

Using anonymised data from phones, Google is plotting the change across a range of different types of location on Community Mobility Reports. The reports cover a wide range of global regions, broken down into retail and recreation, grocery and pharmacy, parks, transit stations, workplaces and residential.

The only area to see an increase in mobility is residential, as people are asked to stay at home. Appropriately, there's a huge drop off in mobility around other areas. What's interesting is that places like parks are seeing spikes, suggesting there are times when these parks are busier.

The aim of these reports is to guide policy makers about how effective the measure might be. It's clear that for the UK there's a huge drop-off across many types of movement - retail and recreation is down 85 per cent - and that's because most of those places - cinemas, theatres, museums, libraries, shopping centres - are all closed. 

The data is compared to Google's baseline data for these types of location, giving a useful picture of how our behaviour has changed over the past few weeks as the social distancing measures have increased.

But what's the source of the data? The data is anonymous and sourced from smartphones that are sharing their location data with Google. That location sharing is off by default, but you're often prompted to turn it on as you use services that make use of location data. If you're worried about your privacy, don't be, as Google gives you all the tools to control whether you share it and to delete your location history if you want.

While many have questioned whether this sort of footfall data is useful - Google Maps will tell you when a restaurant is busy, for example, based on the number of people at that location - in the current climate there's lots of value in this sort of information. If, for example, there's trend that sees mobility increasing in areas at a particular time, it could be that authorities need to step in and either enforce measures, or resolve the bottleneck.