Why hackers posted videos of Elon Musk on British Army’s Twitter and YouTube channels

Hackers infiltrated the British Army’s Twitter and YouTube accounts to promote cryptocurrency scams and on YouTube, they replaced the British Army’s videos with old livestreams featuring Tesla CEO Elon Musk and former Twitter CEO Jack Dorsey.
The UK Ministry of Defence confirmed in a tweet late on Sunday that they were aware of a breach of the Army’s Twitter and YouTube accounts and an investigation was underway.
“The Army takes information security extremely seriously and is resolving the issue. Until their investigation is complete it would be inappropriate to comment further,” the Ministry further posted.
Both the social media accounts were later restored.