Again, there are other variables at play, but generally speaking, turning off the "send information" Spotpass setting gives one an 86.2% chance of not being banned, according to the poll. This poll doesn't take into account other variables, such as the Friend List setting. It's possible many of the 13.8% of people who had the "send information" setting off but still got banned also had the Friend List "show what I'm playing" setting on. We also know that a lot of people in that 13.8% were mistaken and actually did have the setting turned on.
I have my money on the use of eshop
Most go to it either to get legit stuff or for other minor things, but that + CFW and having games installed is a more dangerous cocktail