Users of 4chan are planning to primarily tape up grotesque images all across Dashcon on Saturday afternoon in an attempt to trigger con-goers unless they are paid $17,000 in bitcoin by 7/12/2014 12:00pm central time.
I have gathered this information from /b/ and /pol/ while under a 4chan Gold account, where posts can be made private, inaccessible to anyone without a gold account. They started planning this upon hearing about the Dashcon hotel scam, where the Dashcon Tumblr asked for $17,000 to pay the hotel to avoid getting the con-goers kicked out of the hotel.
I would recommend anyone and everyone avoid the con after noon Saturday to avoid seeing these pictures and other harassment 4chan may be planning.