"Why block this?": what a destination usually sends, and why people block it

When FireAI has background on the kind of destination in front of you, Why block this? shows: what it usually sends, why people tend to block it, what might stop working if you do, and what FireAI has actually measured on this Mac for it — separately from all of that.

If this is the first connection FireAI has seen to that destination, it says so plainly instead of guessing. See answering your first connection prompt for the rest of that screen.