"Non-passive event listener" warning.

[ojvribeiro]

I'm receiving this warning in the console:

[Violation] Added non-passive event listener to a scroll-blocking 'touchstart' event. Consider marking event handler as 'passive' to make the page more responsive.

Should I have to worry?

[juni-vogt]

Not really.
This is what passive event listeners do: https://stackoverflow.com/a/37721906
Sadly, jquery doesn't support them natively. You could work around this, though.
The lib actually currently uses one touchstart listener on the document for every element with ripples while, theoretically, only one global one would be needed.
I did a quick test and, unless you have an obscene amount of ripple elements there shouldn't be an impact.
http://jsbin.com/wanorosupe/1/edit
#11 related