After the well-documented issues at Pokemon GO Fest, leading to refunds and other in-game compensation, some attendees have also opted to file suit against Niantic, the developer of Pokemon GO. Thomas Zimmerman, a Chicago attorney, has allegedly been contacted by several (possibly up to 20 or 30) people for the purpose of seeking legal action against the company. The complaints are based on marketing and fulfillment. While Niantic compensated people for the price of admission and advertised game content, many attendees paid well over the cost of admission for travel and the actual experience of attending the event. Which obviously did not proceed as advertised.
The argument will ultimately boil down to whether or not Niantic is responsible for travel expenses for anyone who chose to attend the event from outside the state or even outside the country. It will then be based on the legal parameters of something like deceptive advertising. This may not be applicable, considering the issues were caused by unpredictable technical issues.
Of course, legal matters are sensitive and Niantic is not keen to speak on the matter at the moment.