Cite? I mean, you can get slammed if you lie and hide assets, but not for simply not paying if you don’t have the $$.
Generally, Bankruptcy does not relieve Tax obligations. YMMV, ianal.
The 2400 exemption was in 2009 because of ARRA.
Point taken but you are splitting hairs here… by the same standard a certain amount of wages are not fully taxable either.
For that matter… a certain amount of wages or other earned income results in a negative income tax…let’s not forget that! 
I see that someone else has posted the year and amount that was exempt from Federal tax… thanks!!
Curiosity from a heavily taxed UK citizen. How much can a single American man earn in a year before he has to pay any tax? over here I can earn £8,105 ($12,200)
A little less than that, it varies by year, call it $10000.
The minimum wage here is £6.19 so for a 40 hour week that’s £12,875 ($19,400)
Remember that everything is more expensive here.