I read an article last week about how activists use screenshot tools like Nimbus Screenshot to capture whole web pages... It saves everything as one image file, which is harder to change or remove. Another thing I heard about is setting up a personal archive with free software like ArchiveBox... It can automatically save copies of web pages you link to, keeping them on your computer. But you need to watch out for storage space, especially if you're backing up lots of media. Sometimes just having offline copies on an external hard drive is the most reliable way, even if it's simple.