1789 -- All Writs Act is passed, giving US courts broad authority to write orders for all kinds of things. This is the law that the US District Court in California relied on to order Apple to write software that will help the FBI crack into the iPhone 5C previously owned by Syed Farook, one of the San Bernardino shooters. The tension springs from whether the law really allows the court to order Apple to create something that doesn't already exist to help with the FBI's investigation.
1993 -- The US government proposes the use of the Clipper Chip, which would help law enforcement listen in on encrypted phone calls with a warrant. The chip was meant to act as a key that can only be turned by the government, but this angered civil liberties advocates, who argued it would lower the quality of American-made phones and violate consumers' privacy rights. Ultimately the proposal became outdated as digital technology progressed.
1994 -- Communications Assistance for Law Enforcement Act (CALEA) is passed, requiring telephone communications companies to assist in wiretapping phone lines. The law was expanded to cover Internet traffic in 2005, requiring Internet service providers to build in the ability to intercept user traffic. Both kinds of surveillance require a warrant. The law isn't being applied in the Apple-FBI conflict because it doesn't apply to data resting on a smartphone.
1996 -- SSL 3.0 is released. It's the software that gave rise to our current system for encrypting data as it flows over the Internet. But, not all your data flying across the Internet is encrypted. Civil liberties advocates and companies are developing more products for more easily establishing encrypted connections, and Canadian networking company Sandvine projects that more than 70 percent of the world's Internet traffic will be encrypted by the end of 2016.
2001 -- The Patriot Act is passed in the aftermath of the September 11 terrorist attacks in the US. The act broadly increased authority for National Security Agency surveillance. Most notably in the encryption debate, it paved the way for the creation of secret FISA courts, which can give the government warrants for surveillance.
2009 -- Operation Aurora. China hacks Google, targeting the Gmail accounts of human rights activists and hitting 20 companies in total as part of the cyberattack. This started a rift between Google and China, in which the search giant stopped censoring its results in China and moved the base of its operations out of mainland China to Hong Kong. Currently, Google services are extremely limited in mainland China.
2010 -- BlackBerry surveillance in Saudi Arabia. Research in Motion agrees to let the Saudi Arabian government access BlackBerry users messages. The agreement arose out of a conflict in which BlackBerry service appeared to have been disrupted inside the country. Known at the time for using strong data encryption for its messaging service and for routing email into Canadian servers that other governments couldn't access, the devices previously had a reputation for securing user data.
2013 -- Former NSA contractor Edward Snowden reveals the extent of government surveillance both of other countries and its own citizens. Central to these disclosures was the cooperation of seven major technology companies in making it easier to divulge user information to the NSA, which the agency then pored through using a computer program known as PRISM. The New York Times named these companies as Google, Microsoft, Yahoo, Facebook, Apple, AOL and PalTalk, saying the companies confirmed their cooperation with FISA-authorized requests for user data. These revelations gave rise to efforts to take user data out of the hands of companies, a strategy that Apple in particular has adopted.
Snowden, seen here, appeared on John Oliver's HBO show "Last Week Tonight" on April 5, 2015.
2014 -- The rise of end-to-end encrypted messaging apps, like Signal, Telegram, WhatsApp, Line, Cyber Dust and Apple iMessaging. These all offer the option to send messages that remain encrypted at all times between two users' devices. Without end-to-end encryption, communications over the Internet are typically decrypted when they reach the servers of the service provider. That means companies like Facebook can read your messages and hand them over to law enforcement, too. But companies that offer end-to-end encryption don't have the ability to unscramble user messages and provide them to the authorities.
2014 -- Apple and Google both announce they'll encrypt phone data by default. And here we are! The biggest smartphone manufacturers in the world make it known they won't have access to your data as it sits on your smartphone. Google later had to amend this announcement to say it would leave this decision in the hands of Android phone manufacturers.