Alaska Airlines joined larger companies in fighting a new fee disclosure rule.Bill Clark/CQ-Roll Call, Inc via Getty ImagesBig US airlines are suing over a rule that requires upfront fee disclosures.The Biden administration is fighting "junk fees" across industries, including baggage fees.The airlines argue that fee transparency will confuse consumers. Major US airlines sued the Department of Transportation on Friday over a rule that requires upfront fee disclosures for costs like baggage and itinerary changes.The Biden administration has made fighting the hidden costs it calls "junk fees" a priority across industries, from banks to event companies.Under the rule, which goes into effect on July 1, airlines have to display fees the first time a consumer sees the fare, not in a hyperlink or separate page.