If you keep one key per device, you can revoke it if/when that device is compromised, stolen, etc..
That key is for initial access to provision your machine, after which you should have a more sophisticated means of managing users, as certainly, if you are doing anything of much importance, you will eventually need at least 2.
By all means, have a separate, passphrase-protected key for each separate device (desktop, laptop, tablet) and push them to your machines using something like chef and the 'users' and 'sudo' community cookbooks, at a minimum, and destroy the .pem after you initially set up the host.
There is a reason that Amazon only configures one user with only one key, and it's not because that's how sane people access their machine.
The port shutdown was about the truckers, though there was some ILWU support - I have personally met ILWU leaders who were in support.
The truckers are not allowed to unionize, are employed as "independent contractors", sometimes have to sit with their engines running, idle, trying to get into the port for hours without being able to pee. They are treated as if they operate a small business while they are in actuality an employee with none of the rights of a typical employee.
The ILWU also doesn't oppose the city or state government interfering with a port shutdown because without the ability to shut down a port, they would not exist.
The anger is that I'm ashamed to be associated with most people in the tech community lately, wherever I can live, and that so many people who just moved to the bay area think they know so much about how they are obviously not impacting it negatively.
People are becoming bigoted against tech folks and it's not a healthy change for this community, but I can't blame them, and frankly most of the time lately I don't want anything to do with people on either side of the polarized debate.
But the discussion is about how Google and whoever are "solving problems" that would be created by people driving private vehicles when in fact they are commonly recruiting people to work in Mountain View by dangling the ability to live in SF in front of them, which is damaging to the entire community as a whole, from Mountain View to SF to Oakland to Berkeley to wherever.
Also I do not live in SF, FYI, I used to, until my own fucking industry priced me out, simultaneously making it impossible to run a small business here providing tech services as I did for many years.
I came to SF to have it change me, but so many people are intent upon changing it, with complete disregard for how the tech industry left the city a husk after the dot-bomb.
I learned a lot of tough lessons about what makes SF SF and how to play harmoniously with that and most people are just spewing entitlement about how it doesn't matter that they are PERMANENTLY driving the cost of living up due to their TEMPORARY ability to make more money.
The truth is that real estate speculators are profiting off people on both sides of the debate.
People are paying twice the rent that would have been paid a few years ago and in many cases not getting better services.
I just don't feel sorry for a few people who got stuck on a bus. Protests are about showing that you can't change business as usual without interfering in it.
The problem is not that Google, Facebook, and others are "solving a problem" by providing these bus fleets. They are offering jobs on the peninsula paying more than jobs tend to pay in SF [because SF companies have to pay more for rent and ACTUALLY PAY THEIR FUCKING PAYROLL TAXES TO PAY TO MAINTAIN THE BUS STOPS], with a greater likelihood of becoming filthy rich, to people largely moving from other parts of the country and/or world, with the promise that they can work in one community and live in another.
When such employees are not being recruited from other places, they are being recruited from SF. Google and Facebook have a problem that their offices are in FUCKING BORING monoculture suburbs which young, smart, energetic people do not typically want to live in. And their big, monolithic companies aren't a great match for the culture of SF, though companies like Twitter have been trying to make it work by insisting that SF is doomed without them.
One has to ask, why do people want to live in SF rather than Mountain View or Palo Alto? Is it because those places are FUCKING BORING?
Yes. And they are not FUCKING BORING because they lack craft cocktail places, they have a monoculture that is unattractive to people accustomed to diversity.
That is why these buses are gross, and that is why it is gross that people who just recently moved to SF after rents roughly doubled think that people should just get a better job if they want to live here, because who ever lived in SF except rich people?
How can someone who moved here as a student and began trying to build a life for themselves in the bay area ever fit without basically letting Larry, Sergei, and Zuck declare the sort of job that people who live in SF can have?
How can people ever own a home in this city if the only way is by being [un]lucky and boring enough to be at a behemoth company or a random startup that couldn't easily be predicted to hit, and take a bunch of stock away?
Also, if SF becomes a place where most people who can afford to live here have to work in another city, it will be largely devoid of employed people during the day. There will be jobs serving coffee in the morning, dinner in the evening, mostly stocked by people who live in the east bay, and we're likely to see some of the crime problems that Oakland has which I believe directly have to do with this, specifically that lots of people who pay rent and mortages in Oakland have to go to another city to do so, on woefully overloaded transit systems that are struggling for funding, leaving the city largely full of unemployed people and violent police officers during the day.
SF is an amazing place and I can't imagine why anyone would only want to work here during the first and last hours of the day, when I do my best to be here as many hours of the day as possible, though I can't afford to live here.
Plus a lot of these assholes don't even like SF. It's like a fancy fucking pair of shoes for them to brag about.
I do about 30h of "work days" and easily more than 10h of off-hours, took me a few changes of venue to remove the requirement to be at my desk 8-9 hours a day, and I am more productive and happier.
That the most sophisticated attacker with the most resources may be able to tunnel into your data is no excuse for lax security.