Dozens of bands and musicians have signed an open letter directed to the organizers of SXSW, demanding that the festival remove clauses from its contract regarding deportation of international artists who play unofficial showcases or act "in ways that adversely the viability" of their official showcase. The artists who have signed the letter include Priests, Downtown Boys, Ted Leo, Sheer Mag, Screaming Females, PWR BTTM, Sad13, Helado Negro, Allison Crutchfield and the Fizz, Hari Kondabolu, Vagabon, Immortal Technique, Ceremony, Girlpool, Anti-Flag, and many more. The letter follows a tweet on Thursday from Brooklyn-based musician Felix Walworth, who wrote that after reviewing the contract, they'd decided to cancel their band Told Slant's SXSW performance. Walworth's statement quickly gained attention, and by the end of the day, several more musicians were speaking about boycotting SXSW. Roland Swenson, managing director of the festival, told SPIN in a statement Thursday evening that Walworth's decision was the result of a "misunderstanding of our policies regarding international artists." One of the contract clauses in question specifies that international artists "entering the country through the Visa Waiver Program (VWP), B visa or any non-work visa may not perform at any public or unofficial shows, DAY OR NIGHT, in Austin from March 10-19, 2017," and that violation of the policy "may result in immediate deportation, revoked passport and denied entry by US Customs Border Patrol at US ports of entry." The other controversial clause specifies that SXSW will "notify the appropriate U.S. immigration authorities" if international artists or their representatives "have acted in ways that adversely impacts the viability of Artist’s official SXSW showcase." The open letter from artists, which you can read in full here, demands that SXSW remove those clauses from its contract with performers, make a public apology, and "affirm that it is a welcoming space for all artists," including immigrants and international performers. In his statement to SPIN, Swenson wrote that the language in question has been in SXSW's contract for years, and that the festival has "never reported international showcasing artists to immigration authorities." Swenson also wrote that the clause regarding deportation of international artists who play unofficial showcases was meant to inform artists of problems they may encounter with U.S. immigration law, not to enumerate a policy specific to SXSW. "For example, those acts coming to SXSW to perform without a work visa are limited, by U.S. immigration law, to performing their showcase event only. If an artist wishes to perform elsewhere, they will require a work visa," he wrote. The provision regarding notification of immigration authorities is intended as "a safeguard to provide SXSW with a means to respond to an act that does something truly egregious, such as disobeying our rules about pyrotechnics on stage, starting a brawl in a club, or causing serious safety issues," he wrote. "We hope never to be put in the position to act on this." The open letter to SXSW does not specifically state that the undersigned artists will not perform SXSW if the demands are not met. However, the rapper Immortal Technique wrote that he is "urging fellow artists to not play there until this is fixed."