Californian authorities filed felony charges against Mason Sheppard, 19.
The UK's National Crime Agency (NCA) confirmed it had searched a property in Bognor Regis with police on Friday.
A teenager in Tampa and Nima Fazeli, 22, of Orlando, were also charged in Florida.
US Attorney David L Anderson said the arrests proved "nefarious hacking... for fun or profit" did not pay off.
Twitter accounts of multiple high-profile US figures were hijacked in an apparent Bitcoin scam on 15 July.