Some have argued that the government should be required to present "specific and articulable facts" showing that the information to be gathered is relevant and material to an ongoing investigation. This is the standard used by Title II of the ECPA with regard to the contents of stored communications. Others, such as Daniel J. Solove, Petricia Bellia, and Dierdre Mulligan, believe that probable cause and a warrant should be necessary. Paul Ohm argues that standard of proof should be replaced/reworked for electronic communications altogether.