Amazon, CBS, eBay, Nike, Target and Viacom are among the 30 major American companies that have signed an amicus brief asking the Supreme Court to rule on Virginia's same-sex marriage ban.

Their rationale is that the uneven recognition of marriage equality in the U.S. places an undue burden on corporations.

Well, if you want to change laws in this country, showing how they hurt corporations is a pretty good start.

An excerpt from the brief:

We are located or operate in states across the country, some of which recognize marriages of those of our employees whose spouses are of the same sex, and others that prohibit marriages between same-sex couples and refuse to recognize existing same-sex marriages.

This dual and continuously shifting regime uniquely burdens amici. This legal uncertainty exposes us, as employers, to unnecessary cost, risk, and administrative complexity.

In addition, this irresolution hampers our efforts to recruit and retain the most talented workforce possible, placing us at a competitive disadvantage. Our success depends upon the welfare and morale of all employees, without distinction.

The burden imposed by inconsistent state laws of having to administer complicated schemes to account for differential treatment of similarly situated employees creates unnecessary confusion, tension, and ultimately, diminished employee morale.

The full list of corporate signers is below. (Note: Logo/NewNowNext is a subsidiary of Viacom Inc.):

Alcoa Inc.

Amazon.com, Inc.

Aspen Skiing Company

Ben & Jerry’s

Bloomberg L.P.

CBS Corporation

Cisco Systems, Inc.

Cummins Inc.

Deutsche Bank AG

Eastern Bank Corporation

eBay, Inc.

General Electric Company

Intel Corporation

Jazz Pharmaceuticals, Inc.

Kimpton Hotel & Restaurant Group, LLC

Levi Strauss & Company

Massachusetts Mutual Life Insurance Company

NIKE, Inc.

Oracle America, Inc.

Outerwall Inc.

Pfizer Inc.

Qualcomm Incorporated

Staples, Inc.

State Street Corporation

SunLife Financial (U.S.) Services Company

Support.com

Symantec

Target

United Therapeutics Corporation

Viacom

A challenge to Virginia's ban filed by American Foundation for Equal Rights won this year in both the U.S. District Court and in the U.S. Court of Appeals. But Attorney General TK is appealing those decisions—and both the state and plaintiffs agree SCOTUS needs to make a final decision.

“This case is about justice and about redeeming the constitutional guarantee of equality for countless gay and lesbian couples that has been denied for far too long,” said AFER executive director Adam Umhoefer. "...We are prepared to argue the case for freedom and equality for all couples across the nation, and the Supreme Court must rule in favor of the fundamental right to marry for all Americans.”