Federal Election Commission voyeurs rejoice! Last-minute super PAC donors are about to be revealed.

More than 70 PACs have spent a combined $81.3 million more than they accounted for in donations before the election. Unless these super PACs found some loan sharks, the spending will be accounted for in last-minute donations that will be revealed in coming hours. Political committees must file their post-election reports with the Federal Election Commission by midnight Thursday. Some are filing early and we're posting as we see interesting tidbits.

Other super PACs are members of what we at Sunlight have dubbed the "October Surprise Club." They didn't start spending until the last month of the campaign, and 49 of them waited until late enough to start giving that they did not have to disclose any donors before the election. Those last-minute givers accounted for $32 million in spending. Many are nonprofit "social welfare" organizations that will never disclose their donors, but those that are run as super PACs will be revealing the sources for that funding this week.

Among the more significant super PACs whose spending suggests they have more to disclose:

American Crossroads is yet to account for $23.8 million in spending. This cycle, American Crossroads spent $104.7 million to sway the electorate. Unfortunately for them, only 1.29% of the money went toward the results American Crossroads wanted.

Restore Our Future, the super PAC that supported Mitt Romney spent $10.9 million more than it accounted for in donations. The group spent $142.6 million promoting the unsuccessful Republican presidential campaign during the election.

New York City Mayor Mike Bloomberg started Independence USA PAC in October; the group only started spending Oct. 22, dodging the pre-election filing requirements by waiting to the last minute. While it's expected that Bloomberg has provided most or all of the money, the filings should answer this question.

Of Now or Never PAC’s $7.7 million in spending, $5 million has not been accounted for in donations. (And with a 14.3% rate of return, on the group's spending, maybe the final answer is “never.”)

Freedomworks for America got large donations last year ,from its sister political non-profit Freedomworks. The super PAC still needs to account for $3.8 million in donations.

House Majority PAC spent $30.7 million in the election, $3 million has yet to be accounted for this cycle.

Like college students, it seems the bulk of the super PACs won't be turning in their campaign accounts until at the last minute.

While the sources of the last-minute spending outlined above will be known by week's end, voters will never know who provided the funds for at least $300 million in campaign spending that was funneled through groups–often 501(c)4 nonprofits–that to not disclose their donors. And a Sunlight Foundation analysis found that there are 18 incoming members of Congress who benefited from at least $1 million in such spending.