I in no way want to start an arguement with anyone but before killing a eagle, hawk or owl you had better check with your state's Game or Wildlife Agency. It does vary for state to state and will require a permit in those few that allow it.
All hawks and owls are federally protected under the Migratory Bird Treaty Act (16 USC, 703-711). These laws strictly prohibit the capture, killing, or possession of hawks or owls without special permit. No permits are required to scare depredating migratory birds except for endangered or threatened species, including bald and golden eagles.
Even in Pennsylvania it isn't easy. According to the Philadelphia Inquirer, in September of 2002, a Chester County PA woman, Gwynne McDevitt, a 71 year old Chrysler heiress, was sentenced to 200 hours of community service and fined $130,000.00 for paying others to kill hawks in or near her property.
Many people are advocating that ever stricter laws protecting raptors be put in place following the conviction of members of an Oregon racing pigeon club for killing hawk and falcon in California and Oregon. Oregon's House of Representative Peter DeFazio has introduced the following- House Resolution 4093, provides penalties of up to a $50,000 fine and a year in jail for intentional killing of migratory birds and up to a $25,000 fine and six months in jail for other violations of the Migratory Bird Treaty Act. Prosecutors would have discretion to prosecute violations as misdemeanors.