Members of both the Senate and the House are pushing the Federal Trade Commission (FTC) to address what they say are unfair ticketing practices in the online ticket resale industry.

In letters sent to the FTC on Sept. 13 and obtained Thursday, lawmakers urge the consumer protection agency to investigate online retailers posing as direct sellers or "private labels."

Sens. Cory Booker (D-N.J.) and Orrin Hatch (R-Utah) said in their letter that aides looked up “Madison Square Garden Tickets” on an internet search engine and found that the top paid result was “madisonsquaregarden.ticketoffices.com,” a domain not affiliated with Madison Square Garden but owned by a third party.

The Hill's own search of “Madison Square Garden” yielded a top paid result from “madisonsquaregarden.eventticketscenter.com/?” a separate third-party site, also unaffiliated with the actual venue.

Booker and Hatch argued that such sites could trick consumers into believing that they're buying tickets directly from from vendors, without additional markups.

"We respectfully ask that the FTC review the use of private labels as vehicles for confusion, price obfuscation, and overall consumer harm," they wrote.

In a separate letter, Reps. Tom Marino (R-Pa.) and Anna Eshoo (D-Calif.) pointed to an FTC case in 2014 over TicketNetwork and its affiliated companies for engaging in similar practices. The company reached a $1.4 million settlement with the agency.

The lawmakers also railed against such ticket sellers' exorbitant service fees, which they say take advantage of consumers.

“Consumers and regulators are used to seeing private labels — in everything from groceries to house cleaning services, in markets online and otherwise. That said, such private labels are liable to abuse if not monitored closely, and especially so online,” Booker and Hatch wrote.