All the info comes from Occupied London - From the Greek Streets.
First we are told what happens with immigrants when they can't be expelled from Greece, usually because their home countries are at war, like Syria, Afghanistan or Somalia. These people should be considered war refugees but they are considered mere criminals because they don't have visa.
When the legal time for them to be kept in prison expires, they are not set free, no: they are kept in prison (an extra cost for the Greek public arcs) illegally for as much as 12 months.
Oddly enough this info was only made public because it is expected to support the plans of the Greek government of building 30 new prisons.
What?! The country is bankrupt, it can't pay pensions and you're wasting the money in prisons?
As you read it.
That's the kind of state and society that Capitalism offers us as we enter the 21st century: a prison state, where you and I have no rights but can be arrested at any moment for no reason. And immigrants are used as pretext.
Then we are faced with a tiny bit of the ugly reality of the Greek police state: cops beating a peaceful foreigner incidentally captured in video:
It's from some days ago and I believe I already posted it but still it is relevant considering that police is doing the same at big scale these days.