I sincerely hope you’re kidding and the people who replied positively are your fake accounts.

By doing that, you’re app will be almost immediately blocked, hopefully banned, and likely also the user accounts banned.

The right way to do it is using fb api under its limitations. In addition, if I recall correctly, you’ll need to refresh user’s token every 30d, so you prob want an excuse for your users to come back to your site frequently, e.g. via an email that shows weekly stats.