Bannon

Bannon is the owner of Potomac Attire and a member of the Rivet City City Council.

Bannon thinks that he is the most important person in Rivet City and when asked about the history of the city, he will tell you he is the founder. This is not the truth. But that doesn't stop him from telling you. He also apparently has a "social problem" (STD) as noted by Doctor Preston on his terminal.

Unmarked quest
When you talk with him you'll get the option to find incriminating evidence on Seagrave Holmes, which can be found in Seagrave's room, Under the bed leaning against the footlocker. The key for the room can be pickpocketed from Seagrave.

Once you have obtained the "evidence", you can report back to Bannon. However, should you decide to confront Seagrave with it, you can use it to remove Bannon from the council and install Seagrave as a council member. No matter which direction you choose, you will have to turn in this "quest" with Lana Danvers in the tower. There is no quest log entry, no experience for completion, and no Karma effect. If you side with Seagrave Holmes in your conversation with Lana Danvers, then return to Seagrave, he will grant you a 10% discount on stuff you buy and will give you 10% more for stuff you sell. Inversely, Bannon will give you 10% less for the stuff you want to sell and will charge 10% more for the stuff you want to buy from him. Bannon will also give you Deathclaw Gauntlet Schematics upon completion of the "quest", but only if you side with him.

Appearances
 only appears in Fallout 3.