Is double blind necessary or important?

[astraloid]

Is it possible to contaminate the target when the tasker provides the tag to the viewer directly rather than through a mediator?

 

[RVTrainee001]

worse, a third person can hickack your tasking. so viewer's pristine intent is needed

 

[jrb]

I'd heard reference of that hijacking. Wasn't that a concern held by Prudence Calabrese? But are there any published materials where this has been tested?