It has been quite a week for the FBI.
First it got back a large chunk of the Bitcoin paid to the gang behind the Colonial pipeline ransomware attack. Then it led a global operation which saw suspected criminals tricked into using a messaging service operated and monitored by the agency.
On this week's Tech Tent, we explore whether criminals will now think twice about using tech in their activities.
Listen to the latest Tech Tent podcast on BBC Sounds
When it comes to understanding and using the latest technology it has often seemed that law enforcement is always at least one step behind the criminals. Not this week.
Just how the FBI managed to retrieve $2.3m (£1.6m) of Bitcoin paid to the DarkSide ransomware gang is far from clear. Theories range from the agency having an insider in the gang who handed over the private key to the Bitcoin wallet where the ransom had ended up, to the criminals being careless enough to leave their loot in a well-known exchange which could be ordered to hand it over.
Some have even suggested that Colonial only paid the ransom at the behest of the FBI so that the gang could be tracked more effectively.
Whatever the truth, Ciaran Martin, who as former head of the UK's National Cyber Security Centre worked closely with the Americans, thinks life may have been made harder for the criminals.
"There'll be a lot of people now distrusting the payment mechanisms of cryptocurrency," he tells the programme.
"And when there starts to be a bit less trust, that's a good thing."
Suddenly the idea that Bitcoin movements can be tracked - something that cryptocurrency experts have been pointing out for years - seems to have become fashionable.
"Pipeline investigation upends idea that Bitcoin is untraceable," read a New York Times headline this week.
But even when the money has been traced you still need the private key to unlock it and Ciaran Martin warns that the Colonial Pipeline ransom recovery operation may prove a rare success.
"It's so clever and so good, it's quite hard to do it that often," he says.
"To do it again, requires a lot of very clever operational skill, a lot of resources."
On Wednesday it emerged that another ransomware victim, the meat processing giant JBS, had paid out $11m in cryptocurrency to its attackers. Whether the FBI can mount a recovery operation on behalf of the Brazil-based company remains to be seen.
But the operation which saw the FBI and the Australian police fool hundreds of criminals into using a supposedly secure messaging app could prove a bigger blow in the fight against crime.
Spotting a gap in the market after two other encrypted services used by criminals were taken down, the FBI appeared to act like an innovative start-up, seeding devices carrying the Anom network with "key influencers" in the form of alleged crime bosses.
Now, says Ciaran Martin, seeds of doubt will have been sown in criminal minds.
"Any criminal hearing, 'We've got this new gadget that will help us evade the authorities,' will treat it with much more suspicion, even if it actually isn't a law enforcement set-up," he said.
Law enforcement agencies have had to acquire all sorts of technical skills as crime has moved online. But the huge profits derived from cybercrime mean the criminals too are investing heavily in innovative techniques.
The FBI may have had a good week but you can bet the crooks will have their victories in the months ahead.