Paperwork
Paperwork
[Cueball holds his smartphone in both hands and takes a picture of his desk which has several sheets of paper (with unreadable text) lying around on it, hanging out over the edge of the table and also on top of his laptop standing on it. A more than half empty glass of water stands behind the laptop. The shutter sound is shown with small dots around it to indicate the picture is just being taken now.] Phone: Click
[A smaller frame is inside the main frame to the right. It shows Cueball now typing on his phone. Above the frame a "speech" box goes outside the smaller frame but points with a jagged arrow towards the phone. Inside this box Cueball's message is displayed. At the bottom two typical social media buttons are shown, the left of them is grayed out, with gray text inside a thin gray line, the right button has dark text on a dark gray background with a solid black line around, probably to indicate that Cueball has pushed this right button at this very moment.] Ugh, check out how much tax paperwork I have to do. Cancel Post
[Caption below the panel:] I've accidentally discovered the world's most efficient way to leak personal information.

Cueball is complaining on social media about how much tax paperwork he has to do. He posts a picture of all his tax documents to share how much work he had to do before Tax Day . At first this just seems like an innocuous and generic thing people post on social media, but then the caption gives us a sobering reminder (and punchline): Tax documents contain many specific and important personal information in a very small area, like your social security number, address, income etc, and Cueball has just posted all of them for identity thieves to just stumble upon.
It is generally a bad idea to give out personal information like this to anyone, especially people online as this data can be used in many forms of fraud, by people pretending to be you or even using your login to gain access to your bank or other private matters. A picture of this information-dense tax return is the "most efficient" way to leak this critical data short of sending out the actual return.
Lots of people take photos of themselves, others, and objects around them, and post them in public and semi-public places, often without fully thinking about the kinds of personal information they might be accidentally including.  Even if they do examine the photo for personal information and conclude the photo is safe to post, information they think is innocuous might end up being meaningful to someone else, possibly in combination with other public information they might have gathered about a person.
One example of a photo revealing more than was expected is when the Washington Post posted a picture of the TSA master keys .  The photo was detailed enough that people were able to create and 3D print their own working keys.
The title text further adds to the issues. First, it explains the picture was geotagged , which means anyone could easily find Cueball's home. Next, it also says his password manager was on his laptop screen, unlocked and presumably showing many of his passwords, usernames, and other information needed to log in to his accounts (such as email, banking sites, social media sites, etc.), thus allowing anyone to easily get in.  Finally, the title text suggests Cueball's naked body was reflected off the laptop screen, and inadvertently included in the picture. Thus the people wishing to use his information can now potentially blackmail him with this nude picture as well on top of anything else.
With xkcd's stick figures it's usually impossible to tell if they are clothed or naked, but now that we know Cueball is naked in this one it may make this strip NSFW . Thus consider yourself warned.  The nakedness of xkcd stick figures have been mentioned before – for instance, in the third strip of 566: Matrix Revisited , and in 864: Flying Cars where Megan is pictured topless.
Having a picture of oneself naked on the internet, without your own intent or consent, is also generally a bad idea. Many young people (kids) find out when they send a nude picture to a boyfriend/girlfriend over Snapchat that it can be screenshotted. This prevents it from being removed later. And if/when they then fall out of love it might be shared online. Although illegal, this happens often, and causes harm to both the victim (who has been humilated online) and the offender (who can be jailed for this; it is considered child pornography if the nude person is underage).
Both the United States and the United Kingdom have important tax-related deadlines in April, the month this comic was released. In the United States, the 2018 Tax Day fell on April 17, and in the United Kingdom April 6 is the start of the tax year .
Taxes were also the topic of the comic 1971: Personal Data which was released just two weeks before this comic.
[Cueball holds his smartphone in both hands and takes a picture of his desk which has several sheets of paper (with unreadable text) lying around on it, hanging out over the edge of the table and also on top of his laptop standing on it. A more than half empty glass of water stands behind the laptop. The shutter sound is shown with small dots around it to indicate the picture is just being taken now.] Phone: Click
[A smaller frame is inside the main frame to the right. It shows Cueball now typing on his phone. Above the frame a "speech" box goes outside the smaller frame but points with a jagged arrow towards the phone. Inside this box Cueball's message is displayed. At the bottom two typical social media buttons are shown, the left of them is grayed out, with gray text inside a thin gray line, the right button has dark text on a dark gray background with a solid black line around, probably to indicate that Cueball has pushed this right button at this very moment.] Ugh, check out how much tax paperwork I have to do. Cancel Post
[Caption below the panel:] I've accidentally discovered the world's most efficient way to leak personal information.
