To submit an essay on spec (short for “on speculation”) means to submit a finished, written and polished piece—as opposed to the few short paragraphs in which you would try to sell an idea in a standard article pitch. The obvious downside is that you’re stuck writing the entire thing beforehand, on your own dime, without any certainty the piece will sell. That said, personal essays are a great opportunity to show off your distinct voice as a writer. Editors will be more likely to consider your essay based on its storytelling merits alone, instead of on your portfolio of past work (or lack thereof).
In 2013, a mysterious group of hackers that calls itself the Shadow Brokers stole a few disks full of National Security Agency secrets. Since last summer, they've been dumping these secrets on the internet. They have publicly embarrassed the NSA and damaged its intelligence-gathering capabilities, while at the same time have put sophisticated cyberweapons in the hands of anyone who wants them. They have exposed major vulnerabilities in Cisco routers, Microsoft Windows, and Linux mail servers, forcing those companies and their customers to scramble.