The National Rifle Association is facing a corporate backlash as companies take a closer look at their investments, co-branding deals and other ties to the gun industry following the latest school massacre. A handful of companies have ended discount programs with the NRA as the group aggressively resists calls for stricter gun control after a gunman killed 17 people at a Florida high school last week.

The moves come as petitions circulated online targeting companies offering discounts to NRA members on its website. #BoycottNRA was trending on Twitter.

Members of the NRA have access to special offers from partner companies on its website, ranging from life insurance to wine clubs. But the insurance company MetLife Inc. discontinued its discount program with the NRA on Friday. Car rental company Hertz and Symantec Corp., the software company that makes Norton Antivirus technology, did the same.

“We have notified the NRA that we are ending the NRA’s rental car discount program with Hertz,” the company tweeted Friday.

Here is a list of some of the companies that have cut ties or distanced themselves from the NRA:

• First National Bank of Omaha: The bank announced that it would not renew a co-branded Visa credit-card with the NRA.
• The Hertz Corp.: The rental car company ended its discount program for NRA members.
• MetLife Inc.: The insurer terminated discounts that had been offered to NRA members on the NRA website
• Enterprise Holdings Inc.: The car rental company that also owns Alamo and National cut off discounts for NRA members.
• Symantec Corp.: The software company that makes Norton Antivirus technology ended its discount program with the NRA.
• Chubb Ltd.: The insurer announced it was ending participation in the NRA’s gun-owner insurance program, though it provided notice three months ago.
• Best Western: The hotel chain told multiple social media users that it was no longer affiliated with the NRA, though it did not say when that decision was made.
• Wyndham Hotels: The hotel chain told social media users it is no longer affiliated with the NRA without specifying when that decision was made.
• United Airlines: United said in a tweet Saturday it is “is notifying the NRA that we will no longer offer a discounted rate to their annual meeting and we are asking that the NRA remove our information from their website.”

The swiftness of the corporate reaction against the NRA has differed from that of past shootings, including the 2012 Sandy Hook Elementary School massacre that claimed 26 lives and the killing of 58 people in Las Vegas last fall, said Bob Spitzer, a political scientist at SUNY Cortland and a scholar on gun politics. Spitzer said the reaction was likely a reaction to the student mobilization that followed the Florida shooting, but he said it was too soon tell how significantly it will sway the country’s wider gun debate

“If this is as far as it goes, it probably won’t have any measurable effect. If other companies continue to (cut ties) it can start to have an adverse public relations effect,” Spitzer said. “Usually what happens is that the storm passes, and the NRA counts on that.”

Spitzer noted that it was not the first time big business has been pulled into the gun debate. In 2014, Chipotle asked customers not to bring firearms into its stores after gun-rights advocates brought military-style rifles into one of its Texas restaurants. A year earlier, Starbucks Corp. made a similar statement after the Newtown, Connecticut, shooting.