Wi-fi hotspots: Europol warns against 'sensitive' use
7 March 2014 Last updated at 14:59 GMT
People should not access sensitive information - such as their bank accounts - over public wi-fi, Europe's top cybercrime police officer has warned.
Troels Oerting, head of Europol's cybercrime centre, said the warning was motivated by a growing number of attacks at hotspots.
The BBC's technology correspondent Rory Cellan-Jones explains.