This is a side quest available in the Network Security District while you're doing the bonus series. You're tasked with escorting an Imperial speaker past Hutt security so he can broadcast from a major Holonet hub server, then delivering the speech yourself after he get stomped by droids in a cutscene.
At that point, you can either:
1. Deliver the pre-written speech, described by the quest giver as "a message of intimidation."
2. Deliver a distinctly less intimidating speech (I assume), preview text: "This is a message of peace..."
3. Deliver a personal speech specific to your class.
I picked the last option (preview text for Inquisitors: "Galaxy, I am your master!"), and was treated to one of the single most awesome pieces of writing I've ever heard. All in all, it made me feel just a little bit like
this.
Here are the few bits and pieces I can remember right now of the speech, which runs for about 45 seconds total:
"I
know you can hear me! ... Your fear endears you to me, it makes me strong. I rose from slavery to become Sith, and soon I will rise to be
your lord and master. ... Creatures of the galaxy! ... You will know my name!"