Shydude,
PoPo is an urban/innercity slang term for the police. I was in a downtrodden section of Pittsburgh one day and an elderly lady was yelling "I ain't afraid of the Pittsburgh PoPo" at a police officer. He was merely trying to descalate a parking space dispute. I found it humorous given that she was elderly and in her Sunday best attire. The officer looked speechless. 99% of my posts are in regard to law enforcement activities and frequencies in the Pittsburgh area. Hence the basis for my username.
I suppose you could ask any forum member the basis for their username. As is the case for any forum, each username is, and must be, a unique identifier.
You had originally billed your site as a "New PA Public Safety & Scanning Forum". Now you are identifying it as a "a dual website for scanner enthusiasts and firefighters". Rather than give specifics as to why your website is viable, you merely state you want to be "unique". I must surmise that you do not have specifics.
Given the posts to date, and membership signup rate, I'm guessing your website will serve your immediate geographical area as a mini-social network, as opposed to the previously billed PA Public Safety & Scanning Forum. That's a noble mission for your narrow customer base.
The Ford Edsel was a unique car and Sony Betamax was a unique VCR format..... I wish you well with your unique website. However, neither you or I can think of any reason that it would as beneficial as this site. "Unique" isn't pushing me to sign up for something new that RadioReference already does exceedingly well.