Background: The Beach Boys are an American rock band formed in Hawthorne, California, in 1961. The group's original lineup consisted of brothers Brian, Dennis, and Carl Wilson; their cousin Mike Love; and their friend Al Jardine. Distinguished by their vocal harmonies and early surf songs, they are one of the most influential acts of the rock era. The band drew on the music of jazz-based vocal groups, 1950s rock and roll, and black R&B to create their unique sound, and with Brian as composer, arranger, producer, and de facto leader, often incorporated classical or jazz elements and unconventional recording techniques in innovative ways.
Context: Recorded in the wake of California Music's demise, a supergroup that would have involved Brian Wilson, Bruce Johnston, and record producer Terry Melcher, 15 Big Ones (1976) marked Brian's return as a major force in the group. The album included new songs by Brian, as well as cover versions of oldies such as "Rock and Roll Music", "Blueberry Hill", and "In the Still of the Night". "Rock and Roll Music" peaked at No. 5 in the U.S. Brian and Love's "It's O.K." was in the vein of their early sixties style, and was a moderate hit. The album was publicized by an August 1976 NBC-TV special, simply titled The Beach Boys. The special, produced by Saturday Night Live (SNL) creator Lorne Michaels, featured appearances by SNL cast members John Belushi and Dan Aykroyd.  The album was generally disliked by fans and critics upon release. During its sessions, Brian's production role was belittled as group members overdubbed and remixed tracks to fight against his desire for a rough, unfinished sound. Carl and Dennis disparaged the album to the press while Brian admitted, "[Undoubtedly] the new album is nothing too deep", but remained hopeful that their next release would be on par with the group's "Good Vibrations".  For the remainder of 1976 to early 1977, Brian spent his time making sporadic public appearances and producing the band's next album The Beach Boys Love You (1977), a quirky collection of 14 songs mostly written, arranged and produced by Brian. Brian later called Love You one of his favorite Beach Boys releases, saying that "That's when it all happened for me. That's where my heart lies." Jardine credited Carl and Dennis with having "the most to do with that album ... [they were] paying tribute to their brother." Love You peaked at No. 28 in the UK and No. 53 in the US and developed a cult following; regarded as one of the band's best albums by fans and critics alike, and an early work of synthpop.  Referring to "naysayers" of the album, the underground fanzine Scram wrote, "Fuck [them] ... [the album showcases] a truly original mix of humor and sadness. The original numbers always dance just a step away from the cliche, dealing with simple lyrical themes that make you wonder why they had never been explored before." The A.V. Club - considering the album in "the same vein" as Tonight's the Night (1975), Pussy Cats (1974), The Madcap Laughs (1970), and Barrett (1970) - described Love You as: "something almost desperately optimistic ... Wilson sings frayed songs about roller-skating, road-tripping, and Johnny Carson - like a frazzled man sitting in a corner chanting 'calm blue ocean' over and over. It's a beautiful, noisy, funny, heartbreaking work of art - one not for everybody, yet vital for anyone who wants to understand Wilson's overall worldview."  In 1983, tensions between Dennis and Love escalated so high that each obtained a restraining order against each other. With the rest of the band fearing that he would end up like Brian, Dennis was given an ultimatum after his last performance in November 1983 to check into rehab for his alcohol problems or be banned from performing live with them. Dennis checked into rehab for his chance to get sober, but on December 28, 1983, he fatally drowned in Marina del Rey while diving from a friend's boat trying to recover items that he had previously thrown overboard in fits of rage.  From 1980 through 1982, the Beach Boys and The Grass Roots performed Independence Day concerts at the National Mall in Washington, D.C., attracting large crowds. However, in April 1983, James G. Watt, President Ronald Reagan's Secretary of the Interior, banned Independence Day concerts on the Mall by such groups. Watt said that "rock bands" that had performed on the Mall on Independence Day in 1981 and 1982 had encouraged drug use and alcoholism and had attracted "the wrong element", who would steal from attendees. During the ensuing uproar, which included over 40,000 complaints to the Department of the Interior, the Beach Boys stated that the Soviet Union, which had invited them to perform in Leningrad in 1978, "...obviously ... did not feel that the group attracted the wrong element." Vice President George H. W. Bush said of the Beach Boys, "They're my friends and I like their music". Watt later apologized to the band after learning that President Reagan and First Lady Nancy Reagan were fans. White House staff presented Watt with a plaster foot with a hole in it, showing that he had "shot himself in the foot".  The band returned to D.C. for Independence Day in 1984 and performed to a crowd of 750,000 people. On July 4, 1985, the group played to an afternoon crowd of one million in Philadelphia and the same evening they performed for over 750,000 people on the Mall in Washington. They also appeared nine days later at the Live Aid concert.  In 1985, they released the eponymous album The Beach Boys and enjoyed a resurgence of interest later in the 1980s, assisted by tributes such as David Lee Roth's hit version of "California Girls". "Getcha Back", released from the album, gave the group a No. 26 single in the U.S. Following this, the group put out "Rock 'n' Roll to the Rescue" (U.S., No. 68) and a cover of the Mamas & the Papas' "California Dreamin'" (U.S., No. 57).  In 1987, they played with the rap group The Fat Boys, performing the song "Wipe Out" and filming a music video. It was a No. 12 single in the US and a No. 2 rank in the UK.  By 1988, Brian had drifted from the Beach Boys and released his first solo album, Brian Wilson. During this period the band unexpectedly claimed their first U.S. No. 1 hit single in 22 years with "Kokomo", which had appeared in the movie Cocktail, and soon became the band's largest selling single of all time. They released the album Still Cruisin, which went gold in the U.S. In 1990, the band gathered several studio musicians and recorded the Melcher-produced title track of the comedy Problem Child. The album Summer in Paradise, had no new contributions from Brian because of interference from caretaker Eugene Landy.  A lawsuit was filed by Brian in 1989 to reclaim the rights to his songs and the group's publishing company, Sea of Tunes, which he had supposedly signed away to his father Murry in 1969. He successfully argued that he had not been mentally fit to make an informed decision and that his father had potentially forged his signature. While Wilson failed to regain his copyrights, he was awarded $25 million for unpaid royalties. With Love and Brian unable to determine exactly what Love was properly owed, Love sued Brian in 1992, winning $13 million in 1994 for lost royalties. 35 of the group's songs were then amended to credit Love.  In 1993, the band appeared in Michael Feeney Callan's film The Beach Boys Today, which included in-depth interviews with all members except Brian. Carl confided to Callan that Brian would record again with the band at some point in the near future. A few Beach Boys sessions devoted to new Brian Wilson compositions occurred during the mid-1990s, but they remain largely unreleased, and the album was quickly cancelled because of personal conflicts. In February 1996, the Beach Boys guested with Status Quo on a re-recording of "Fun, Fun, Fun", which became a British Top-30 hit. In June, the group worked with comedian Jeff Foxworthy on the recording Howdy From Maui, and eventually released Stars and Stripes Vol. 1 in August 1996. The album consisted of country renditions of several Beach Boys hits, performed by popular country artists such as Toby Keith and Willie Nelson. Brian acted as co-producer.
Question: what is the most important fact listed in the article?

Answer:
In 1983, tensions between Dennis and Love escalated so high that each obtained a restraining order against each other.