https://beta.observablehq.com/@observablehq/playground has 3 issues with Firefox (63.0.3) + uBlock Origin.
uBlock Origin blocks the call to vega.github.io, resulting in
NetworkError when attempting to fetch resource.
uBlock Origin AND native Firefox tracker protection block the call to the
the twtter thing is visually broken.
(Would it be a good idea to add a category “Feedback on notebooks” in this forum?)
(I can reconfigure my browser, but since this is a notebook intended to welcome beginners, it suppose it ought to work for everyone, as much as possible.)