Nintendo’s Swapnote is a fun little app for the Nintendo 3DS that allows you to send notes, pictures, and audio. This uses SpotPass to send these to your friends as long as you have their friend code. Sadly, Nintendo has decided to drop this feature of Swapnote due to abuse of the system.
Nintendo posted to their official website saying that the feature is being removed due to consumers, including minors, giving out their friend codes online and using Swapnote to exchange offensive messages.
We are very sorry for any inconvenience to the many consumers who have been using this service responsibly; however this decision was made considering the point that many minors also use this feature of Swapnote. Thank you for your understanding.
Sadly this case is one where a small group of people have to ruin the service for everyone else.