Alan Shatter (Dublin South, Fine Gael) | Oireachtas source

It is because, clearly, if there was an issue arising under the legislation there may be information of a sensitive nature that would be very damaging if revealed in public. It may identify the sources of information. It may pose a risk to the security of the State or it may pose a risk to the lives of those who provided information. Clearly, offences would have to be proved beyond reasonable doubt. There will still be the proper level of proof, but we cannot have a criminal prosecution which is designed to deal with issues that could affect the security of the State or deal with matters of criminality in circumstances where, if the prosecution takes place, information could be revealed that could give rise to difficulty.

This type of provision is not unusual in the context of this type of measure.