EV DA offers the option to configure the option to ensure that a recipient has to be specified before a search can be performed to avoid the possibility of having a search being performed against the whole Journal Archive. This can be achieved by setting the " Require 'Recipients' to be specified" within the Configuration Settings.
However, this setting is not currently being honoured and a search will still be performed even if no recipients is specified for the search.
This issue has been addressed as part of the following release:
Enterprise Vault 9.0.3 - Release Details
Enterprise Vault 10.0.1 - Release Details