Even though the Pirate agenda is rather social-liberal in its traditional political way, Pirate party has its own economical agenda which emphasizes as rather both non-marxist and non-capitalist.
Liberal ideas are more concentrated on capitalism, whereas Pirate ideals concentrate on Digital Economy, Distributism/Georgist economical ideals, replacing the standard capital with virtual, rather.
Liberals tend to provide too much power to digital intellectual property, whereas Pirate ideology tends to reduce its power and/or eliminate it. Some Pirate radicals even support elimination of Copyright itself (marxist way), while maintaining real life private property (liberal way).
Some Pirates support nationalization of petroleum reserves in order to protect nature ( socialism ), and in the same time zero-taxes for green energy companies ( liberal )
Traditional politics like socialism and liberalism tend to maintain the same political position in all contexts:
-> Liberals want everything to be private. Full capitalistic.
-> Socialist-Communists want everything to be public & nationalized. Full socialistic.
The term Pirate is exactly what represents supporting a direct/liquid/participative democracy ( completely opposite to Emanuel Kant’s vision of democracy ), digital economy, digital free culture, etc.
It began with the liberation of slaves and giving black people and women the power and rights they never had. That’s how equality began. And the Pirate social roots are there, from the Free Republic of Nassau, a self-governed short-lived land with participative universal suffrage democracy.
Pirate ideology encompasses the Virtual, as a independent anarchic & free space, a second reality that helps our stable reality thrive, through Free Culture. That’s why the term Pirate, it is used to protect and maintain virtual reality as it is.
Liberalism / Socialism philosophies never actually encompassed or thought of something like virtual reality. The philosophers couldn’t include such a thing in their political philosophies, because it didn’t exist back then.
Nowadays each philosophy tries to adapt itself to virtual reality, and failing horribly, creating monsters like ACTA, European Copyright Directive, and so forth.
In Europe, both liberals and socialists, and conservatives, communists and almost all of the european politics spectrum, supported Copyright Directive. Pirates did not. This is the ideology and term, we protect the free Internet, which is rather in our ideology, and our future.
Also, one more note:
-> Liberalism proposes the irregular expansion of property and business, without proper power balance. Pirates are on the other side of the story: support expansion, but decentralize power. Hence, why the pirate term is not coined as also-Liberal.