I understand being upset about the tracking aspect, but attaching query params to a link isn't breaking anything. Of all the ways Facebook could have implemented something like this, I actually prefer it this way. Query params are easy for me and other adblockers to strip off. Imagine if they were messing with request headers or something that was harder to notice or change.

An incredibly small number of sites might already be using `fbclid` internally, and an even smaller number won't be able to update their sites.

I am totally on board the don't-break-the-web train, but this just doesn't seem like a problem to me. Maybe once stats come out we'll see that it's a bigger issue, but... I kinda doubt it.