>1. having the quality or power of creating. >2. resulting from originality of thought, expression, etc.; imaginative: creative writing. >3. originative; productive (usually fol. by of).
Adding blinking gifs to a homepage does not create anything, it does not result from any originality of thought nor is is productive so I would argue that it is not hacking.
The word "hacking" has, in the media, taken on a meaning which is different from the meaning that it had originally - and the meaning that you'll most often find around here. Sadly, though, the use is so common that arguing against it is pretty much hopeless. It seems that outside of the hacker community (proper sense of the word), you probably shouldn't call yourself a hacker, since the first thing that will come to people's minds is this.
This isn't hacking. This is 'cracking' - and a more disgusting form of it than usual, a form meant to physically harm people.