Poland to Suspend Schengen During Warsaw Climate Change Conference
08 November 2013
"The suspension of Schengen rules will mean additional checks at Poland’s borders with the Czech Republic, Germany, Lithuania and Slovakia, and at all airports and seaports.
A statement from Poland’s Ministry of Internal Affairs reads: “Polish Border Guards may prevent entry into Poland of anyone who may disrupt public order or pose a threat to security.”"
See:
Poland to Suspend Schengen During Warsaw Climate Change Conference (Krakow Post, link)