Network tab of the Firefox developer console shows a forbidden/blocked kind of sign in the "Status" column, mouse hover over it shows only "Blocked". The "Transferred" column contains "Tracking". Mouse hovering over "Tracking" here on a Network tab or on a Console tab, does not show any detail.
Layman user who is trying to discover what was blocked and why, do not know which FF setting or extension blocked the element. I think that the column has more space to mention "Blocked by XY, setting ABC" or similar.