I've been excited about this card since I first saw it here a couple months ago. It is going to be huge versus two of the three major runner factions. Here are a few scenarios:
I see you are counting on your Datasucker to back up your Parasite. Sorry, my Archer has a quiver-full with your name on it.
Perhaps you think D4v1d will back up your weak @ss breakers? Nope, Susanoo is sending you to archives for the Shock! of your life.
Have you ever spent nine influence on the Grail suite just to then have the runner drop a SMC on the table? I have, and it sucks. So much for your big surprise. Navi prevents SMC from firing though. Artist Colony and Clone Chip won't work either.
I don't see this being as helpful versus Criminal, but there are literally a ton of cards that this will stop provided it is rezzed first.
EDIT: It is funny that despite my excitement over this card, I have yet to use it. As beladee mentioned though, there is now an extremely common criminal card that this can help thwart, Aaron Marron. I really need to try this out in my tag heavy deck.