Options to flag/report malicious and inappropriate links

Some idea has to be developed so that Linkbook is not misused for storing content that shouldn't be on our site.

My idea - Employ a 'Flag as inappropriate' option, which sends mail on 3 or 5 flags to us to request action. Banning the user may be another dimension that can be thought upon at later stages.

@nikhilkumarsingh @himanshugupta1997 if you have any improvment in mind do mention