Taylor Swift's ex Conor Kennedy arrested with his father during global warming protest outside the White House By Snejana Farberov Taylor Swift's environmentally minded ex-boyfriend Conor Kennedy ended up in handcuffs after taking part in a high-profile protest over global warming outside the White House Wednesday. The 18-year-old Kennedy heir, who had enjoyed a brief summer romance with the country singer, was arrested along with his father, Robert F. Kennedy Jr, actress and activist Daryl Hannah and dozens of others. The protesters had attached themselves with zip-ties to the gates of 1600 Pennsylvania Avenue in an act of civil disobedience meant to draw attention to the controversial Keystone XL oil pipeline. Trouble: Conor Kennedy, son of Robert Kennedy, Jr., is arrested after tying himself to the White House gate to protest the Keystone XL oil pipeline High-profile arrest: Conor's father, Robert F. Kennedy Jr, was led away by police along with dozens of other protesters committing an act of civil disobedience The group were demanding that President Obama reject the proposed project, which they say would carry 'dirty oil' that exacerbates the growing problem to global warming. As the 48 arrested protesters were being led away by police from the presidential residence, a crowd of spectators cheered Conor and his father by name. Summer fling: Singer Taylor Swift, 24, left, dated 18-year-old Conor Kennedy for several months and even visited the family compound in Hyannis Port, but their relationship proved short-lived According to a press release from the Sierra Club, which also participated in the rally, 'After being taken away from the White House in handcuffs, both Kennedys were driven to a Park Police station and released after paying a fine.' "For the first time in the Sierra Club's 120-year history, we have joined the ranks of visionaries of the past and present to engage in civil disobedience, knowing that the issue at hand is so critical, it compels the strongest defensible action," Michael Brune, executive director of the environmental group, told RadarOnline. We cannot afford to allow the production, transport, export and burning of the dirtiest oil on Earth via the Keystone XL pipeline. President Obama must deny the pipeline and take decisive steps to address climate disruption, the most significant issue of our time. Under the proposal currently before the president, the pipeline would transport heavy crude oil from Canada to the U.S. Gulf Coast. Robert F. Kennedy Jr., a renowned environmental lawyer who heads the organization Waterkeeper Alliance, called the Keystone pipeline a "catastrophic and criminal enterprise" that will enrich a few while "threatening the future of civilization," according to a statement cited by the Huffington Post. Conor Kennedy, who is still in high school, dated the 24-year-old Swift for several months over the summer. The happy couple were photographed flocking on the beach in Cape Cod and spending time at the Kennedy compound in Hyannis Port, Massachusetts, Yahoo! OMG reported. Defiant: Actress and activist Daryl Hannah flashes a victory sign as she is arrested outside the White House gates Civil disobedience: Hannah, center, was one of nearly 50 protesters who took part in the rally calling on President Obama to reject the controversial oil pipeline At the height of their fling, Ethel Kennedy, the matriarch of the clan, even publicly said that she 'should be so lucky' to have Swift become part of the family. The Grammy-winning 'Trouble' songstress even purchased a mansion for $4.5million across from the Kennedy estate, but her relationship with Conor proved short-lived. Swift soon turned her attention across the pond to One Direction singer Harry Styles, also aged 18, but their hot-and-heavy love affair did not last long either.