Troels Oerting , head of European internet crime center , told the BBC that Dan Simmons of Internet users should only send personal data over the network they trust .
He said the warning was motivated by the increasing attacks via Wi - Fi in public areas .
Europol helping countries tackle such attacks , said Oerting .
Data stolen
" We have seen the abuse of wi - fi to steal information , identity or keyword and money from users who are using a public connection or wi - fi is not safe , " he said .
