According to Ben Smith at Politico, the IRS is about to do something HUGE with regards to anonymous funding. This may end up killing (or at least drying up a good chunk of their funding) before they get off the ground in 2012.
IRS Gift Tax Move Could Hit New Anonymous Groups
It appears that the IRS Estate and Gift Tax team has also started paying attention to 501(c)(4) organizations," a Los Angeles tax lawyer who has followed the issue closely, Ofer Lion, wrote in a memo to clients today.
Gifts to other political organizations are not taxable under federal law, and lawyers informally say many donors do not typically pay the gift tax -- which may run as high as 35%, mirroring income tax rates -- for contributions to 501(c)4s.
This essentially means that donations to these types of organizations could hit as high as 35% in terms of taxable income. It would have to be reported to the IRS. This would make those rich individuals (who dislike taxes) think twice before contributing to these groups as their funding would be taxed. The IRS is going to focus in particular on HIGH INCOME FOLKS (Think Koch Brothers, Soros, etc.)
In fact it's already begun, there's part of a letter that a client of a reader of Smith's ha
http://www.dailykos.com/story/2011/05/10/974931/-Breaking:-IRS-to-go-HARD-after-American-Crossroads-Priorities-USAs already received this letter: