Might very well be true, but a lot of this type of stuff also turns out to be folklore. I'd ask for a more authoritative source where I can at least tell what kind of effort went into the research. But, even the Urban Dictionary site has another derivation:
3. The way I've heard it is that sagging was a way for guys in prison to show that they had a gang behind them, or that they were in charge of a large group of inmates. It was like saying "here's my ass, go ahead, TRY to rape me."
Might very well be true, but a lot of this type of stuff also turns out to be folklore. I'd ask for a more authoritative source where I can at least tell what kind of effort went into the research. But, even the Urban Dictionary site has another derivation:
3. The way I've heard it is that sagging was a way for guys in prison to show that they had a gang behind them, or that they were in charge of a large group of inmates. It was like saying "here's my ass, go ahead, TRY to rape me."