Bryon Tau for the WSJ:

Some of America’s largest corporations have finally gotten the memo that election-season giveaways requiring proof of voting are actually illegal under federal law.

It’s an issue that recurs with every election: Companies ranging from national brands to small businesses see an opportunity to both promote themselves and a civic cause by offering discounts or freebies to people with an “I Voted” sticker.

But such giveaways run afoul of federal prohibitions on providing incentives or inducements to vote—a longstanding anticorruption measure designed to facilitate clean elections. Such prohibitions are rarely if ever enforced against corporations offering discounts or freebies to voters doing their civic duty, but they remain on the books.

This year many national chains are keeping their giveaways on the right side of the law by making them available to voters and non-voters alike….

Rick Hasen, a law professor at University of California, Irvine, and perhaps the foremost chronicler of such lawbreaking in recent election cycles, appeared surprised at how many national chains have gotten the message.

“I feel like now I can retire. Looks like all of these Election Day giveaways do *not* require proof of voting (such proof runs into the federal law against inducements to vote, but have been common in earlier elections),” he wrote on Twitter this week.