This one was actually pretty simple. An acquirer filed a 1099 in the incorrect category. We submitted an amended one, but the IRS wants to tax at teh higher rate. And, with giants penalties and interest. You basically have to a) pay the amount they incorrectly claim you owe plus the interest and penalties up-front. Then beg for your money back and b) pay lawyers to try to get them to actually respond. Once the IRS has your money, it's pretty much impossible to contact them and argue. The actual form we filled out, the 843, is pretty simple.
[As an unrelated point, if you're in CA, the current cap gains rate is 15% federal + 9.3 CA income + 1% CA mental health=25.3%. If if goes to the proposed 20% federal + 3.8% medicare + 9.3% CA income + 1% CA mental mental health=34.1%, that's a 34% increase on the taxes on startups in the course of a year... Granted, I care more about the hassle, but it's made me think.]
I also angel invest. Thus far, those companies aren't that old, but my marginal contribution is worth at least several jobs.
When they make it a hassle to create startups and to invest, I spend less time building startups and more time chilling at home. When they make it more expensive, I do less angel investing. It's hard to quantify--I can't tell you how much impact it has on me personally (though it definitely has some). But when instead of looking at me individually, you look at the expected values across aggregates, economists show real, substantial effects.
And, time many, many hours I've wasted on forms, letters, arguments, etc recently are all time that could have been spent coding or with customers.