All bricks are blocks but definitely not vice-versa, and these certainly don’t have the dimensions or material of a standard brick.
I couldn’t find what they were made of but the material is quite white to allow for painting, and reasonably dense. The point is to buy one, paint/draw/spray your message on it and place it within the structure, so they are obviously weatherproof. The proceeds go to care for mentally disabled people.
There are legitimate street events featuring bricks, such as Akce Cihla (Beneficial Brick)

It’s this June and only a 1-minute walk away from where I saw a cybertruck in Prague last month… Unrelated ofc

so it’s not about throwing bricks at people :(
Those look suspiciously like blocks.
I know, I think those people might actually be androids with screens for faces
All bricks are blocks but definitely not vice-versa, and these certainly don’t have the dimensions or material of a standard brick.
I couldn’t find what they were made of but the material is quite white to allow for painting, and reasonably dense. The point is to buy one, paint/draw/spray your message on it and place it within the structure, so they are obviously weatherproof. The proceeds go to care for mentally disabled people.