Hmmm it is true that the government developed the atom bomb in secret and certainly the military has advanced technologies.. I just read Ivanontech's post which is similar to this one and currently Google say they are within 5 years of creating a quantum computer to completely outmaneuver anything we have today, which could then be used to brute force the hashing function of the block, which then would change the entire blockchain. This could be done in a way where millions or billions of bitcoins could then be falsely created and lead to inevitable hyperinflation which would of course destroy the currency's trust and value. So in my opinion it is possible, and if the government sees cryptos and specifically bitcoin as a major threat, I can see why they would invest to ensure they have full control over it.