Redditor delverofsecrets sets the scene:
Dear Reddit, I work in NYC, and was dragged into a very curious situation today. I was taking the 1 train from midtown to the financial district and as usual, the train was pretty packed. I bumped into a raggedy dressed man as we got on and he shot me a quick smile. I though nothing of it until he went to get off at 14th street and he handed me a $50 bill along with a note. Before I could even open my mouth to ask him a question, he was gone.
After some initial skepticism, one user noticed that the word "Bifid" was spelled out in Hebrew along the bottom next to the word "cipher" in Russian. This led them to the "Bifid cipher" — a complex encryption system created by French codemaster Felix Delastelle in 1901.
From there it was only a matter of plugging the letters into the cipher to produce the following sentence (courtesy of SirSpam28):
There's plenty more money to make. Figure this out and prepare to meet July 19th, 56th & 6th. There's a hot dog stand outside Rue57 cafe. Ask for Mr. Input.
Shortly thereafter, delverofsecrets claims he received a private message from Mr. Input himself, with an additional string of characters to be deciphered using the same system. Redditor MrNewking stepped up and provided the solution:
YOU HAVE MANAGED TO FIND THE MESSAGE WITH THE HELP OF FRIENDS. YOU CHANGED THE RULES NOW SO WILL I. JULY TWELVE FOUR PM. FIND THE BLUE JAY AT SIX AND A HALF AND FIFTY SIXTH AND TELL HIM YOU ARE THE LAST.
Now, what does this all mean? No one knows for sure.
Some immediately jumped on the fact that the original date corresponds with the North American release of The Dark Knight Rises and surmise that it could be part of a PR stunt that leads to a prescreening. Clearview Cinemas Ziegfeld, which has a showing at 7 PM, is located near the address provided by "Mr. Input," as is Gotham Skincare.
Also, the Dark Knight has a history of "cryptic" viral marketing campaign that lead to free prescreening passes.
Others, however, have noted that Mr. Input's IP address appears to suggest he is situated in Fort Huachuca, AZ, which just so happens to be NETCOM's command center, where a "Sensitive Compartmented Information Facility" named after a famous cryptographer is located.
To support the job application theory, Redditors pointed to a similar stunt used by Google to find suitable applicants.
Ultimately, there is only one way to find out the truth: Seek it out. But be careful: As Redditor sundaes notes, there's always the chance it's "the ol' 50-dollar-and-bifid-cipher bj trap..."
UPDATE: So it seems nothing actually happened. A bunch of people showed up and mobbed a man dressed in all blue who is apparently a retired Columbia University professor named Fred. He had no idea what was going on — or did he? — so the crowd left to stand in front of an establishment with a blue sign called "J's Cleaners." That went bust in a hurry, so people just wandered around for a while until OP showed up many minutes late. According to reports, he didn't really do much of anything except give out his phone number, get IDed by some cops, and then leave.
Something could still happen on July 19th, but it's unclear who will be paying attention after today's disillusioning experience.