Every time you encounter a suspicious profile in battlelog you put it on your local player list.
BUT how about sending this profile on a shared list on a server wich is sorted by regions (e.g. europe, usa ...). Each Region-List can be activated by the user of this plugin.
You could also use this server to compare the matches on the servers for you. It would bring much more speed and you could put huge lists of thousands of players in without a lag of time.

Just one of thousand reason why not,...
... this lists are completely bad. Every player mark there personal "bad" players/servers.
So nobody can control and imagine what others mean.
Impossible to handle.
Sorry, Rejected - I discused a lot with other about a global banlist - The end of each disussion is each the same, not realizable.