Nintendo is going a little overboard imo. They should have expected that by early shipping one of the most anticipated titles of the year to stores across the world, that there would inevitably be some leaks. If they wanted to avoid leaks, they shouldn't have shipped until the week of release. On top of this, it's just dedicated fans that are eager to show other fans what new Pokes are out there and to be excited about. It's not like the game is being pirated/leaked onto the internet (That I know of) and ruining actual revenue for them.
Hell, if anything, this is just getting more people hyped, which would lead to more publicity/sales for them.They really need to calm down, coming down on the very fans that love and purchase their games is not the right way to go about things.