Having witnessed first hand an unprovoked assault by four officers in Stary Rynek Poznan, I am preprepared to side with szczecinianin to a certain extent but not fully.
You might be interested in reading a first hand account: sz-n.com/2013/12/detained-by-the-police-in-warsaw-a-lazio-fan-tells-his-story/
Please note that no-one has come up with any account of the Lazio fans having caused any kind of major disturbance that does not come from the police themselves.
Which is a bit odd, considering this was a high-profile match in a capital city.
Of course, football fans aren't particularly popular, which means the police can act any way they choose, and most people won't care less.
Ironside: in this case a I think it was about high ranking officials who made that decision that riled szczecz so much
Apparently, it was. It had little or nothing to do with the behaviour of the Italians themselves.