Whangarei couple Leslie and Molly Taka employed modern technology and a false identity to sell crayfish illegally on the internet.
The duo, aged 46 and 42, used someone else's name to advertise their delicious crayfish catch on the social media network Facebook.
And as the word spread on the web there were plenty of buyers who collected their kaimoana in exchange for cash from a Tikipunga home.
That was until officials too used modern technology to track down the illegal transactions.
The couple appeared in the Whangarei District Court on Monday both charged with selling fish not recorded or reported in accordance with the Fisheries Act. They pleaded guilty and were each fined $1000.
Only registered commercial fishers, licensed fish receivers or dealers in fish, such as fish shops, can sell fish, including crayfish.
Breaking the law carries a maximum fine of $250,000 and forfeiture of any property or equipment used.
On December 31 last year officials were tipped off about a person selling crayfish on a Facebook group "Buy Sell Swaps Whangarei".
The seller was sent a message and a deal was made to pay $25 for a crayfish, to be picked up from a house in Tikipunga.
During January officials were made aware of three other online sales of crayfish and seafood by the same person.
A plain clothed fisheries officers went to the house and did a deal with Mr Taka to buy a freshly cooked cray for $50 on January 18, 2013.
Mrs Taka handed over the crayfish. Later that day fisheries officers went to the house and the illegal online selling was exposed.
Judge Maude said the black market sale of crayfish undercut the legitimate licences sellers of fish.
Ministry for Primary Industries Northland compliance manager Darren Edwards said recreational caught crayfish had allegedly been offered for sale on the social media site for $20 to $30.
"The main reason for this is to ensure that all commercial activity is captured at the point of extraction - the commercial fisher - and recorded into the quota management system," Mr Edwards said.
"It's illegal for recreational fishers to sell, offer to sell, or trade for other goods or barter fish that they have caught. Recreational fish is there as a personal entitlement."
Suspicious activity can be reported by phoning 0800 4 POACHER (0800 476 224).