I don't know how it's applied in practice, but apparently the treaty establishing ESA specifies that its space activities will be "for exclusively peaceful purposes" and they apparently have no missions that are classified or have any declared military purpose.

I think there are other non-ESA European (and national) agencies that work on military use of space. For example, there's apparently an "EU Satellite Centre" based in Spain that is concerned with military use of space (and is not part of ESA).

https://en.wikipedia.org/wiki/European_Union_Satellite_Centr...

I do imagine that military users can probably buy or access data from ESA sources on the same terms as civilian users and that they probably do so.

They have much much better resolution though. They can detect car plates, and probably also people looking up.