On Sunday I've seen many such blue things around the Silesian Stadium, and almost in whole Silesian Culture and Recreation Park. I wonder, what it is. And, yes, now I know! -- Blue cloaks of Ruch Chorzów fans used for local derby (soccer match Ruch Chorzów - Górnik Zabrze, 0:1; 40 000 fans, 13 of them were arrested...). PS. The local derby was a reason for TV to come to Chorzów.
Chorzów[ˈxɔʐuf] is a city in Silesia (coordinates: 50°18′N 18°57′E), southern Poland with around 114,680 (2006) inhabitants and an area of 33.5 km². Chorzów is situated on the Rawa river on the Silesian Highland in the heart of the Upper Silesian Industrial Area, 7 km north-west of Katowice. Chorzów is in the middle of Upper Silesian Metropolitan Union, the largest legally-recognized urban entity in Poland with a population of 2.2 mln. The population of the urban area in the conurbation around Chorzów is about 3.5 million. (From Wikipedia.)