The Reddit Mystery: an ARG or something creepier than that?

The mystery, which seems to be generating a lot of online buzz, started when Reddit user ‘delverofsecrets’ posted a note that he obtained from a homeless man in New York City (see image above).
Collective Intelligence
The note contains some sort of a cryptic code, which was deciphered rather quickly by the Reddit community. Now that’s a perfect example of how powerful collective intelligence can be. Deciphering the code resulted in the following message:
Twitter