While I can totally understand and appreciate the anger, frustration, irritation, etc... of my fellow residents, I think we need to be cautious about one thing...painting a wide ranging group with the same brush.
I started my SL as a basic account holder, and remain one to this day. It is what drew me into the realm of SL, and I am very thankful for it. I have since opened a premium account as well...because I believe in supporting something if you enjoy it. However, as sometimes happens in life; funds can occasionally become tight for various reasons...so there have been times when I have had to disable the premium account for a time.
During my time in SL I have been very fortunate to not encounter too many people with whom I have had any problems. There have been the occasional encounters...but for the most part everyone I have met has been warm, friendly, and generally a good person.
I am certain that many (if not the majority) of the people I have met have been basic account holders. I really do understand the concern over free accounts driving the rash of grid attacks...but if you strike down all free accounts as the result of the actions of a handful of thoughtless people...then you will greatly limit your access to a wide range of interesting, entertaining, and good hearted folks...while only having a limited impact on attacks.
Do you really think that the people responsible for finding ways to hamper our enjoyment, wouldn't still find ways to attack SL? It might rid you of the children that just use exploits they've read about on hacking sites...but it will do nothing to stop the more sophisticated attackers that initially discovered those very exploits in the first place.
Regrettably, as with all things SL related...just as some folks find pleasure in building, designing, and entertaining...there are others out there that take their pleasure in destroying, disfiguring, and limiting the fun of others.
Don't let the juvenile assaults of some cause you to discard an entire segment of the SL community...you'd likely find that in the long run such a move would simply result in a far less vibrant community.
Of course that's just one gal's opinion.