1 Next year, instead of buying TurboTax, I'll just let the Chinese government file my taxes for me.

-j

2 They don't really *need* to.  A copy of all IRS records can probably be had for the low, low price of a half-billion-dollar donation to the Clinton Foundation.

3 The one small positive thing is that this sort of information is much more valuable if people don't know you have access to it.  Just assume that everything you tell the government - and everything you don't tell them, given their pervasive snooping - is immediately repeated to your worst enemies.

4 But Pixy, my government *is* pretty much my worst enemy at this point...

There's more angles than (immediate) blackmail as well.  A security clearance would also indicate things like what someone might be susceptible to...and suddenly Mr Gambler has new best friends.  Or Mr. Zipper is targeted by a honeypot.  
We'll be feeling the impact of this for a generation or two.

5 We should assume that they also have all of our Tax Records.   Though I'm not sure how valuable those are to the Chinese government.
We can also assume they can read a copy of the TPP!  And all of Hilary Clinton's emails.

6 I'd say they'd find all of this pretty valuable. You reveal your deepest, darkest secrets to the government during a security clearance, so that you can't be blackmailed with the threat of losing your job. Doesn't mean you can't be blackmailed with the threat of losing your public reputation. 

Heck, everybody in the government is now conducting public policy with, "The Chinese government has my security clearance file." in the back of their mind. Bet US policy becomes, just generally, more favorable to the Chinese, because so many government employees are afraid to piss them off.

Anyway, the argument about whether the government can be trusted with our data is now conclusively over, though the advocates for the panopticon state won't admit it: We now conclusively know the government can't be trusted with our secrets.