Even if Barton didn't tell Loki about the tower, it was still all over the news.
6 seconds sound clip from the The Avengers (2012) movie soundboard.
You can hear this line at 00:57:42 in the Blu-ray version of the movie.
Quote context
[...]
- Doctor?
- A warm light for all mankind.
- Loki's jab at Fury about the Cube.
- I think that was meant for you.
- Even if Barton didn't tell Loki about the tower, it was still all over the news.
- The Stark Tower? That big, ugly building in New York?
- It's powered by an arc reactor, a self-sustaining energy source.
- That building will run itself for, what, a year?
[...]