CIA
by Jeff
Image text: It was their main recruiting poster, hung up nearly ten feet up a wall! This means the hackers have LADDER technology! Are we headed for a future where everyone has to pay $50 for one of those locked plexiglass poster covers? More after the break ...
This comic is a reference to the recent attacks by a group briefly known as LulzSec, which was a splinter group from the internet community known as Anonymous. Anonymous has been a previous subject of xkcd comics. In the back of the news report in frame one is the logo that was used by LulzSec. The group was able to publicize several high profile attacks. They were able to briefly take down the CIA website using a DDoS attack. DDoS stands for Distributed Denial of Service in which the attacker uses many computers to send traffic to a host and render it incapable of answering requests from any other computer, effectively taking the site down.
This comic is pointing out the difference between what lay-people and the computer experts hear when seeing a story like this. It is comparing a website to a company's poster, which is much different and less harmful than the actual hacking of actual computers.
Unpickable
by Jeff
Image text: The safe is empty except for an unsolved 5x5 Rubik's cube.
This comic is a response to the widespread hacking and stealing of people's personal information from company's databases as of late. The companies like Sony amongst were supposed to protect the information, but instead they used flawed security and hackers were able to get in and obtain people's information. (Could be, but likely not, a much better explanation is below in "UPDATE".)
This comic is saying that the only way that you know that your information will be safe from hackers is to keep if offline and in an uncrackable safe.
I'm not sure what the image text means, but I'm sure there is something in there about geeks liking Rubik's cubes or that Randall's only valuable possession is a 5x5 Rubik's cube.
UPDATE: Or it could be a distraction for any geek/hacker that is able to get into the safe. All of the above is true, however, this comic says the hacker will be distracted trying to get into the safe and will ignore the shoebox containing all your valuables. (I blame my misinterpretation on the early morning.) Once in the safe, the geek/hacker will be even more distracted by the 5x5 Rubik's cube. (Thanks commentors!)
Manual Override
by Jeff
Image text: I think you mean 'GNU Info Override'.
In this comic, the pilots of the plane type "man override" into their autopilot and instead of getting "manual override" they get the manual page for the override command. "man" is the command that will pull up the manual entry in Linux distributions of which GNU is one.
Basically this is a pun on the word "Manual", which can mean both "by hand" or "instructions".
The image text is an expansion of the phrase "man override". In the GNU Linux distribution, more information are found in the unwieldy GNU info pages. So, they sub "manual" in the second definition above for "GNU Info".
Permanence
by Jeff
Image text: This hostname is going in dozens of remote config files. Changing a kid's name is comparatively easy!
This one is self-explanatory. Cueball thinks it is easier to change a person's name than to change a hostname of a server because of the number of changes that would need to be made. However, it seems that Cueball has never had to wait in line at the Social Security Administration office or at the Department of Motor Vechicles. Those two name change processes make finding and changes dozens of hostfiles look like a piece of cake.
In the comic, Megan references "epidural" which is a process used during birth that blocks both pain and sensation, which Megan refers to as "drugs".
Progeny
by Jeff
Image text: I tell my children 'it's not whether you win or lose, it's how you play the game.' I'm trying to take the edge off their competitive drive to ensure that I can always beat them.
This comic seems to be a reference to IBM's computer called "Watson" that beat humans at Jeopardy. The IBM team created a computer that could listen to the answer from the host, Alex Trebek and then answer it in the form of a question. In case you are not familiar, that is the format of the game show, Jeopardy. When going up against two Jeopardy champions, Watson was able to beat them both.
Megan chimes in that we are "pretty awesome at teaching" - which I think she is referring to the fact that we are pretty good at programming computers to beat us at different things.
The image text seems to be pretty much a random statement, unless he is comparing the programming of the computers to the teaching of children. There is contradiction in the statement, because he is telling his children that it is not all about winning, so that he can continue to win against them.
Turtles
by Jeff
Image text: You're a turtle!
This comic is pretty unclear as there is not a lot of hints here, but here's what I can make of it. The comic says "Turtles have it figured out, man" because Turtles are never in a hurry to get anywhere because they cannot move very fast (and this one in the comic hasn't moved an inch in 50 years) and they do not have the stresses of a modern human life.
The character offscreen in the comic gets stressed out in the first frame because he or she thinks they deleted a file on their computer. All the while the turtle only thinks "I am a turtle".
The image text appears to be a reference to comic 231 which represents the graph about Cat Proximity in which the saying is "You're a cat!".
Headache
by Jeff
This comic is about 10 images so that it can present the 3D effects, so head over to xkcd if you have not already to check out the comic with the 3d effects. (UPDATE: I have placed a screenshot above.)
Image text: I'm only willing to visit placid lakes, salt flats, and painting exhibits until the world's 3D technology improves.
This comic is probably a reference to the new Nintendo 3DS handheld video game system that has a 3D effect if you put your head in the right place for the handheld device. Also, it is a reference to the proliferation of 3D movies. The 3D movies and 3D games make your eyes work harder which can cause headaches in some.
In this comic, Cueball is using the excuse that 3D gives him a headache to get out of going outside, where obviously, everything is in 3D. Instead he stays inside and looks at his 2D computer monitor. In the image text, he says he will only go to places with little 3D motion.
On a side note: Megan is wearing her helmet and practicing safe bike riding. Way to go Megan!
UPDATE: Thanks commenters - because today is April 1st, all of the xkcd comics are in 3D, so go back and check them out. Which one is your favorite in 3D?
2009 Called
by Jeff
Image text: 2017 called, but I couldn't understand what they were saying over all the screams.
In this comic, the first reference is to the "Three Wolf Moon Shirt", which was an internet meme back in 2009 and earlier. Just like most internet memes it became one just out of thin air. Here's the three wolf moon shirt:
In addition, this comic contains the typical insult "<insert some year> called and they want their shirt/hat/software/whatever back". And in this comic, Cueball quickly turns the insult on its head by asking Megan why she didn't tell the year 2009 about the upcoming earthquakes in Haiti and Japan in the year 2010 and 2011 respectively.
Although it looks weird, I think in the corner of the first frame is a pile of dirty clothes, which is why Megan finds the shirt in it.
The year 2017 in the image text could be a reference to the Arnold Schwarzenegger movie Running Man, which is set in 2017. Or it could be a reference to the Bruce Willis movie Surrogates, which was also set in that year. It is probably an Arnold reference though.
Time Management
by Jeff
Image text: I never trust anyone who's more excited about success than about doing the thing they want to be successful at.
Oh, the irony. In this comic, the image text is in direct opposition to the scenario laid out in the comic. The character in the comic loves time management, but is terrible at it. And the image text tells us that Randall, the author of the comic, hates the type of people who are fake like the character in the comic.
Server Attention Span
by Jeff
Image text: They have to keep the adjacent rack units empty. Otherwise, half the entries in their /var/log/syslog are just 'SERVER BELOW TRYING TO START CONVERSATION *AGAIN*.' and 'WISH THEY'D STOP GIVING HIM SO MUCH COFFEE IT SPLATTERS EVERYWHERE.'
Sorry for the late post on this, I was traveling yesterday. Good thing this comic is not very deep. If you are not familiar with this phenomenon, some sites with mobile versions redirect any link to the main site. Which, is one of the most annoying things in the world.
This comic attempts to explains this away that servers have short attention spans. As soon as they discover it is time to serve the mobile site, it forgets about the sending the proper link.
In the image text, the /var/log/syslog is a reference to the location that Linux Operating Systems keep the system logs.