Many users have reported getting the following message from Snapchat:
After the warning, Snapchat links users to a support page dedicated to the topic, which essentially repeats the same statement, but does add in a serious consequence for ignoring the warning. Snapchat says that it may permanently lock user accounts if they don't stop using 3rd party apps.
Of course, this isn't a death sentence for 3rd party Snapchat apps. Last month, Snapchat did say that it is working on official APIs, which will allow those apps to make a comeback. We'd hope that those APIs are on the way soon though, because otherwise, there may be some upset developers and users when Snapchat starts to crack down.