How to remove attribution in Leaflet?
The Leaflet way: L.map('map', {attributionControl: false, etc...})
A simple $('.leaflet-control-attribution').hide()
or non jQuery document.getElementsByClassName( 'leaflet-control-attribution' )[0].style.display = 'none';
.
Vladimir himself says it's OK to remove it: https://groups.google.com/d/msg/leaflet-js/fA6M7fbchOs/JTNVhqdc7JcJ, but it seems like you should leave it or acknowledge Leaflet in some way.
This is perfectly explained in the Leaflet API reference for map options.
For those using react-leaflet, use:
<Map attributionControl={false} />