Add JavaScript to disable the right click on SharePoint.
To simplify the story, we use Content Editor Web Part to ad in the JavaScript. Enter code below in “Source Editor”:

<SCRIPT language="JavaScript">
function queryString(parameter) {
var loc = location.search.substring(1, location.search.length);
var param_value = false;
var params = loc.split(”&”);
for (i=0; i
param_name = params[i].substring(0,params[i].indexOf(’='));
if (param_name == parameter) {
param_value = params[i].substring(params[i].indexOf(’=')+1)
}
}
if (param_value) {
return param_value;
}
else {
return false; //Here determine return if no parameter is found
}
}
function right(e) {
if (navigator.appName == ‘Netscape’ &&
(e.which == 3 || e.which == 2))
return false;
else if (navigator.appName == ‘Microsoft Internet Explorer’ &&
(event.button == 2 || event.button == 3)) {
alert(”Sorry, you do not have permission to right click.”);
return false;
}
return true;
}
document.onmousedown=right;
document.onmouseup=right;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
if (document.layers) window.captureEvents(Event.MOUSEUP);
window.onmousedown=right;
window.onmouseup=right;
</script>