The screensot says it all.
On Redacted there was even more graceful thing: "Hack acquired no items".
I'd be more in favor of a "Hack acquired no items" message. If there is no feedback on a hack, people will think it is buggy.
There is also a bug where if you glyph some portals and quick-hack other portals you start getting "Bonus items" pop-ups with no items in them, even though you did in fact receive the items.