Polish rules of evidence prohibit the use of any witness testimony or confession which has not been in conditions of freedom of expression. There are many possible reasons of the exclusion of freedom of expression in a particular case – many of them are obvious or clearly indicated in art. 171 § 5 of the Code of Criminal Procedure. However, there are also less intuitive reasons for the exclusion of the freedom of expression such as psychological manipulation. Existing manipulative interrogation techniques use very advanced psychological coercion methods and they pose a serious threat to freedom of expression