Marcelo Bielsa’s decision to send a member of staff to spy on Derby ahead of their clash with Leeds has got the whole football world talking.
On the day of the game, the Derby Response Unit revealed that they had caught a suspicious man at the perimeter fence.
But it was the hashtag they used that got people talking.
They ended their tweet with “#SpyingIsCheating.”
Was this man an employee of Leeds and been ordered to spy on Derby?
Well, that theory was confirmed by Bielsa in his pre-match interview ahead of the match on Friday night.
"I am responsible for this incident. It's not about being legal or illegal or right or wrong," he admitted on Sky Sports.
"Yesterday I talked to Frank Lampard and he told me I didn't respect the club.
"I have my view but what is important is what Lampard and Derby think. I'm responsible for it and didn't ask the permission of Leeds United to do it.
"I have been using this practice since the qualifications of the World Cup in Argentina. It is not illegal and we have talked about it publicly and in the press."
Derby boss Frank Lampard was furious - and so too were many football fans.
But Bielsa didn’t actually break any rules and there are some fans that don’t feel the Argentine has done too much wrong.
But Gary Neville’s reaction may have been the best of the lot.
After chief football writer of The Times, Henry Winter slammed Bielsa, Neville decided to hit back at the high-profile journalist.
“Surely sending spies daily to climb fences / hide in bathrooms with windows overlooking the training pitch to watch England sessions and disclosing your own countries team and tactics would be worse . No ?” Neville replied.
Neville is clearly digging Winter out for his role in snooping on England training sessions in years gone by and producing reports based on his findings.
And football fans loved seeing Neville call out the journalist - with more than 5,000 retweets at the time of writing.
Neville soon followed that up with his honest opinion of Bielsa’s spying by tweeting: “I can’t agree with it but I admire him for fronting up and also stating he’s always done it. In Spain, for example, it’s quite normal.”
But he still wanted a response from Winter and, once again, asked about his role in spying on the England side.
“Now onto my question?” Neville asked.
We doubt Winter has an answer for him…