The second law in question is the Hatch Act of 1939. Officially called "An Act to Prevent Pernicious Political Activities", the Hatch Act was originally put in place to prevent federal employees from joing an organization that wants to overthrow the government (it was big during the "red scare" of the 1950s).

Today, the Hatch Act allows Federal employees to participate in political parties, but prohibits them from engaging in political activity while on duty, in a government office, wearing an official uniform, or using a government vehicle.

Bottom line: You can't do political work while physically in the White House or using a government email account.

Karl Rove's email use
The issue, of course, is what Karl Rove's involvement was in the firing of the Federal Attorneys. If he had involvement, his emails were likely to shed some light on the extent of that involvment. The desire to examine those emails is what's driving this political issue.

Rove apparently has at least two email accounts. The first is his official White House email account on EOP.GOV (EOP meaning Executive Office of the President). The second is a political email address running on the domain GWB43.COM (GWB43, of course, referring to George W. Bush, the 43rd President of the United States).

In the March 27th Press Briefing, White House Deputy Press Secretary Dana Perino stated:

What I know -- I checked into this -- is that certain White House officials and staff members who have responsibilities that straddle both worlds, that have responsibilities in communication, regular interface with political organizations, do have a separate email account for those political communications. That is entirely appropriate, especially when you think of it in this case, that the practice is in place and followed precisely to avoid any inadvertent violations of what is called the Hatch Act. And so there are some members of the administration that do straddle both worlds. And so under an abundance of caution so that they don't violate the Hatch Act, they have these separate emails.

Bottom line: To keep politics off the government servers, Rove used the GWB43.COM email account.

In the April 13 White House Press Gaggle, the following exchange indicated there might be more than these two accounts:

Q Okay, this is a quick two-parter. Karl Rove, I'm told, has multiple email accounts during this whole time at the White House, and he's conducted business over multiple accounts, not just two.

MS. PERINO: It's our understanding that those all funnel into one place.

Question: How many accounts in total does Mr. Rove have? Where?

Technology in use
Obviously, we don't have a detailed insight into exactly what technologies are being used in toto, both by Mr. Rove and by other members of the White House staff. We do, however, have certain pieces of the puzzle, courtesy of Deputy Press Secretary Perino in her White House Press Gaggle on April 13. In specific, we know: