Activists in Amsterdam have targeted a Microsoft datacenter construction project in an escalation of opposition to large data facilities. Extinction Rebellion said it was behind the action, which involved balloons filled with a chemical substance being thrown at the site.

Based on the available details, the material was aimed at concrete and steel connected to the build. The incident stands out from more typical demonstrations against datacenters, which often focus on public meetings, signs and other non-destructive forms of protest.

The action highlights the intensity of resistance some tech infrastructure projects are now facing in Europe. Datacenters have drawn criticism in various communities over their scale and wider environmental impact, and this case shows that objections around such developments can spill into direct action.

Microsoft’s project is now part of a broader debate over how major technology companies expand physical infrastructure and how far activists are willing to go to challenge those plans.