WASHINGTON (AP) — George Papadopoulos, taken by surprise by FBI agents at an airport last summer, now tweets smiling beach selfies with a Mykonos hashtag. Rick Gates, for weeks on home confinement with electronic monitoring, gets rapid approval for a family vacation and shaves down his potential prison time. Michael Flynn, once the target of a grand jury investigation, flies cross-country to stump for a California congressional candidate and books a speaking event in New York.

The message is unmistakable: It pays to cooperate with the government.

That’s an age-old truism in any criminal investigation, but it’s especially notable in a case as pressing and high profile as special counsel Robert Mueller’s Russia probe, where deals afforded to cooperators have raised speculation about incriminating information they’re providing.

The perks of cooperation have manifested themselves in freer travel, lenient punishment prospects and even public comments by defendants that might have been unthinkable months ago. They form a counterpoint to the experiences of Paul Manafort, the former Trump campaign chairman who has refused to cooperate and faces decades in prison, and send a message to others entangled in the Mueller probe that they too could receive favorable treatment if they agree to work with investigators.

“There’s no question that it’s in the government’s interest to take what steps they can to show that cooperating is in the interest of the defendant,” said Daniel Petalas, a former federal prosecutor. “A basic principle of plea bargaining is that you have to make it worth it to the defendant to admit liability in a criminal matter.”

The latest example came Tuesday when Dutch lawyer Alex van der Zwaan was sentenced to 30 days in prison for lying to the FBI. Though his plea deal didn’t explicitly require cooperation, the charge he pleaded guilty to carries a maximum five-year sentence and it’s likely the attorney, whose wife is pregnant in London, risked a longer punishment if convicted at trial. U.S. District Judge Amy Berman Jackson said some incarceration was necessary to deter others from lying to investigators.

To be sure, defendants who admit guilt are stained with criminal convictions, forego liberties including the right to vote, put their jobs and reputation at risk — and can still wind up with tough sentences. Given that uncertainty and stress, it’s common practice for prosecutors looking to induce cooperation to make concessions, such as dismissing charges or agreeing to recommend a lighter sentence, especially for someone they think can help them build a case against a higher-value target.

“There is a societal interest, frankly, in having people cooperate with prosecutors because often the government only can know what’s happened based on documentary evidence and witnesses that it speaks with,” said Sharon McCarthy, a former federal prosecutor in New York. “But insiders who can give insight into conversations and planning and things like that are crucial to being able to make cases.”“