Twitter turns 10 tomorrow (March 21) and I have the privilege of being a guest of CanadaAM to talk about the impact the social communication service has had since it launched. Interesting fact… I joined Twitter as user 11,600 on November 6, 2006 after Chris Brogan and Julien Smith told a group of us about the nascent service at PodCamp Boston.

There are many “defining moments” that have become part of Twitter’s lore. These include American James Buck tweeting “Arrested” (April 10, 2008) from the back of an Egyptian police car, the role Twitter played in Arab Spring (2011) and the famous Grammy-groupie championed by Ellen DeGeneres (March 2, 2014). I’ve compiled my own list of defining moments, many of which I’ve picked because they’re remarkable though often overshadowed by other stories.

1) Coming of age: Iranian election and the U.S. State Department

Say what you will about the “coming of age” moment for Twitter, for me the undisputed winner the U.S. State Department asking Twitter to reschedule a planned maintenance window to ensure uninterrupted access to tweets from the ground in Iran during that country’s 2009 elections. The tectonic plates of the Internet shifted that day.

2) Live from inside a plane crash

One month before a U.S. Airways plane landed on the Hudson River, Mike Wilson tweeted just seconds after a plane he was in crash landed and burst into flames in Denver. Breaking news and the concept of media sources were forever changed.

3) Crisis mapping and emergency support for Haiti

Patrick Meier was one of the first people to mine Twitter for an immensely valuable crisis mapping effort following the January 12, 2010 earthquake in Haiti. He identified where help was needed most and, among other things, where well-stocked pharmacies were accessible and open for business. Their information was used by military search and rescue teams, FEMA and other humanitarian organizations. Twitter suddenly became indispensable during natural disasters, humanitarian emergencies or other crises.

4) California Wildfires

Twitter cut its teeth as an emergency communication channel during the California wildfires of 2007. Nate Ritter and Dan Tentler aggregated and curated important information about evacuations, essential supplies and meeting places. The two collected information from multiple sources including news reports, SMS messages and others’ tweets on a single stream of activity.

5) Twitter’s first mention in the House of Commons

Twitter entered Canadian Hansard for the first time on October 20, 2009 when MP Ujjal Dosanjh stood up in the House of Commons to declare “I inadvertently tweeted about matters that I ought not to have tweeted about” (40:2 Hansard – 96; 2009/10/20; 1505). Watch the video here.

6) Twitter influences Canadian federal policy

[Correction, April 3, 2016: @robertjensen2 issued the first #TellVicEverything tweet. Read more.]. In protest of Bill C-30, the Protecting Children From Internet Predators Act, @godott @robertjensen2 invited Canadians to oblige then-Public Safety Minister Vic Toews with tweets about their personal lives using the hashtag #TellVicEverything. In two days, 15K Canadians issued 30K #TellVicEverything tweets revealing voting intentions, hygiene habits, dinner plans and MUCH, MUCH more. Minister Toews acknowledged the campaign was “actually very amusing and very pleasant” on CBC Radio’s The House that weekend, just two days before he abandoned the bill.

7) SPVM embraces Twitter, and “nails it” with #manifencours

The Service de Police de la Ville de Montréal (SPVM) coined the hashtag #manifencours on Twitter as part of an effort facilitate safe protests by students during the winter/spring of 2012. The students and public embraced the hashtag which included safety suggestions from the SPVM’s Twitter account to students during active demonstrations. The trust-building interactions over Twitter created the conditions for the students to cooperate. Read more about this amazing story.

8) Hélène Campbell effect

Ottawa’s Hélène Campbell was in desperate need of a double-lung transplant when she kicked off the #beanorgandonor campaign on January 19, 2012. She invited people to help her get Justin Bieber to tweet about organ donation. By the time Bieber delivered on January 21, Campbell had already inspired more than 18K tweets and a 300% increase in donor registrations in Canada. Bieber inspired another 40K tweets and even more organ donor registrations.

9) GoC embraces e-diplomacy

Being effective at Twitter is more than just having a message to deliver and condensing it to 140 or fewer characters. It’s often about crafting a message in a way that attracts and retains attention, and hopefully inspires some form of action or a shift in attitude. The @CanadaNATO smackdown of Russia was heard around the world, and it did so without telling the public to “share if they agree.”

10) #IdleNoMore changes Canadian protests

The Idle No More movement took Canada by surprise starting in December 2012. For the better part of two months, the movement dominated news coverage for a number of reasons including the way it seamlessly straddled the physical and digital worlds. Unfortunately for the movement, it seemed to be caught by surprise with the sudden attention and apparently didn’t have the capacity to harness the onslaught of support. Download a report on #IdleNoMore and the role of Twitter during the movement’s first six months.

Here’s to another 10 years. Happy birthday, Twitter!