Patentability and reach of laws
In the UK you cannot patent 'an intellectual process', but in the USA you can. So in the USA the RSA cryptographic algorithm is patented, but in the UK it is not, and cannot be, and neither can any encryption algorithm.*
As has been noted above, it is odd that SAS first sued in UK and EU courts rather than US courts. One can only assume that they were unaware of European legal precedents. But as for the USA believing that it's laws cover the world, they did pass an act that basically said if a country did not have an extradition treaty with the USA, then USA agents could abduct wanted people from that country legally (possession being nine points of the law). Of course even our great leader, Alexander Boris de Pfeffel Johnson was half USAn, until they wanted tax on selling his main residence, then he decided to keep the money and lose the joint citizenship.
The real issue I have with USAn 'justice', is that it seems ALL judges are political appointees. Were you on trial in the USA and requested a judge affiliated with neither the democrats nor the Republicans they would be unable to oblige. So political corruption seems to be at the heart of the USAn system, with judges, however decent upright and honest they be ( yes, Brett Kavanaugh, I am looking at you ) beholden to a political ideology and interpretation of the law. (Not that I'm claiming the UK system is clearer or better, mind, as I don't understand it either.) Any USAn with knowledge, please, I beg you, correct me on this.
Anyone remember Ferranti? The UK company which bought a USA company, then discovered the USAn concept of 'off balance-sheet debt'. They basically spent a lot of money buying a big debt and the USA judges decided that was ok, and Ferranti went bust, unable to service the debt that was not listed on the balance sheet, the directors of the company they 'bought' walked away with millions.
*(OK, yes, I know that Clifford C Cocks of GCHQ found it before Rivest, Shamir and Adleman published and patented it, but the example is what I'm using here.)