The translation is:
To all our readers
There are now many people unjustly posting copies of manga on the internet. These unjust copies are inconsistent with mangakas' feelings. They are also distorting the authors' intentions of "I want the work to be read this way". The actions of posting these unjust copies on the net, into which the mangakas have poured their hearts, are not only hurting mangakas in real life but are also against the law, even if done in a light-hearted manner. Every time we discover such "unjust copies", we talk to the mangaka and consider every possible countermeasure. But the number of inconsiderate people is great, and at present we cannot deal with all of them. We have a request for all our readers. The unjust internet copies are deeply hurting the manga culture, mangakas' rights, and even mangakas' souls. Please understand once again that all of that is against the law. Also, the mangakas and Shueisha will severely deal with any unjust copies found on the internet. We ask that our readers please continue to support us.
~Weekly Shounen Jump editorial department
This morning people were tweeting Kubo congrats on this 400th chapter when the chapter hasn't even been released in Japan. Smart, guys. Really smart.