Chrome Browser Extension - Highlight Content

I want to create a Chrome browser extension where users can highlight information on websites. That information gets sent to our server via http. They can only highlight a maximum of 1,000 characters and are limited by how many highlights they can do per day. They can also create a username which can be tied to their Facebook account. Users will register on the app itself. It will collect their name, email, facebook url and possibly a few other fields. They can also create a group and project. They can associated highlights to a certain group or project in a drop down menu when they highlight. So when they highlight it will send -username -group project -highlighted content to our server via http. Thank you and let me know if you have any questions.