Thanks to all!
Trejder, you are right, the words "Network Shield" should be translated too, of course - but I can copy them from other (already translated) parts
As for the longer description: while it may be "nicer", it's also longer... and when it keeps appearing in the bottom part of your screen, it may get rather annoying when overlapping other windows. So, I'd rather keep it short.
Last question: should it be
Zablokowano or
Zablokowane, as suggested in the previous post (or doesn't matter)?