Two important themes that George Orwell explored that are still relevant today are disinformation and surveillance.
Winston Smith works in the Ministry of Truth. His job is to constantly rewrite history to suit the most recent developments in current affairs. The slogans promoted present things in terms of their opposite, such as War Is Peace. This endless shifting of the concept of truth can be likened to the 21st-century proliferation of "alternative facts" and fake news. Many people in contemporary society are quick to accept information they read, especially on the web, without trying to verify it.
Another significant theme that Orwell treats is the constant surveillance under which Oceania's people live. In their case, it is the single-party state that always has its eye on them. This is personified as Big Brother Is Watching You. Today, totalitarian regimes do exist, and other countries that are ostensibly democratic have only one political party. The greater similarity to contemporary society is the 24-7 surveillance. Cameras are everywhere, on the street and in the home. While many people voluntarily put themselves under surveillance with smart-home devices such as Google's Nest, the technology is so easy to hack that they are exposing themselves to others' scrutiny.