Planet Money has been talking about LIBOR for a while now and they had some terrific pieces on it recently.
One thing they point out is that it's really hard to figure out the effect of Barclays manipulating the rate since LIBOR is averaged using 18 different London banks with the top 4 and bottom 4 thrown out. So one bank shouldn't make a difference. But there is some evidence of collusion between banks, and even if they didn't collude they might have all been doing it out of self interest.
But we don't know yet so it's possible there was actually no effect from this. (But probably there was.)
Anyway, after the financial crisis hit none of the banks wanted to admit they were unsafe so they gave artificially low LIBOR scores. A low score means they can borrow money cheaply because they are sooooo trustworthy.
Banks like to appear completely safe especially when they aren't, so they all said "we're 100% fine" and reported low scores.
But all sorts of loan contracts reference LIBOR. A house or credit card loan might be set at "LIBOR plus some percent" so when it's a teeny bit lower it might be good for individuals.
But if things like cities or pension funds bought bonds that were based on a lower LIBOR then those bonds are paying out less, so the city or fund is out some money.
I have no idea how it affects the stadium bonds. Thinking it through as a layman: the stadiums were selling bonds to raise money, so if they were based on LIBOR they could have been paying out slightly higher or lower interest than they should have been. But if they sold all the bonds then they got their money anyway so they wouldn't be hurt much, unless a slightly lower rate means fewer people bought them. But if the rate was higher than it should have been then they'd be paying out higher interest than they should which is bad for them, unless this is what enticed people to buy the bonds in the first place.
I'm not an expert in any way, everything I know about this is from Planet Money (which I -heart-). Here are some blog posts on it and a really good podcast episode (as if this wasn't long enough already):
This blog post talks about who the victims were -- scroll to the end if you like. http://www.npr.org/blogs/money/2012/07/0…
This is a short version of the LIBOR scandal, which I mostly summarized already but this has an audio version plus transcript:
And this is the full 20 minute podcast that talks about it in a really approachable and fascinating way: