Letters to officials, letter-writing campaigns, petitions, email and phone campaigns, and demonstrations are options for influencing the public agenda. Letters are read by officials and their staff to gauge public opinion, and should clearly state the issue and position. Letter-writing campaigns can have greater impact by generating many letters. Petitions are like letters but with many signatures to demonstrate support. Email and phone calls are also tracked by officials. Demonstrations can draw media attention but risk public backlash if disruptive or violent.