Who knew? Banking giant Citigroup has trademarked "THANKYOU" and is now suing technology giant AT&T for how it says thanks to its own loyal customers. This is "unlawful conduct" amounting to wanton trademark infringement, Citigroup claims in its federal lawsuit.

Here is a copy (PDF) of the trademark certificates and trademark applications connected to what Citigroup is calling its "THANKYOU Marks."

According to Citibank's lawsuit (PDF) lodged Friday in New York federal court:

For many years, Citigroup has used trademarks consisting of and/or containing the term THANKYOU, including THANKYOU, CITI THANKYOU, CITIBUSINESS THANKYOU. THANKYOU FROM CITI, and THANKYOU YOUR WAY, in connection with a variety of customer loyalty, reward, incentive, and redemption programs (collectively, the “THANKYOU Marks”).

In its lawsuit, the financial institution says AT&T is infringing Citigroup's intellectual property because of AT&T's brand new marketing campaign (PDF) connected to AT&T's co-branded, Citigroup credit card called "the AT&T Universal Card." AT&T is illegally marketing the phrases "thanks" and "AT&T THANKS," Citigroup claims. This "is likely to cause consumer confusion and constitutes trademark infringement, false designation of origin, and unfair competition in violation of Citigroup's rights," the suit says.

Because of "AT&T's unlawful conduct," Citigroup wants unspecified damages and is demanding that a federal judge block this alleged illegal marketing campaign. In its lawsuit, Citigroup said everybody knows that the "THANKYOU Marks" are synonymous with Citigroup.

As a result of Citigroup’s longstanding, extensive, and widespread use, marketing, and promotion of its THANKYOU Marks and services, Citigroup’s THANKYOU Marks are widely recognized by the general consuming public as a designation of source for Citigroup’s high quality financial services and customer loyalty, reward, incentive, and redemption programs.

Not to be outdone by Citigroup, AT&T in April applied (PDF) to trademark "AT&T THANKS." Citigroup wants that trademark to be rejected because it thinks that proposed trademark is "confusingly similar to Citigroup's "THANKYOU Marks," according to its lawsuit.

No hearing date has been set.

THANKYOU for reading!