I doubt u would have many problems englishman the way phones were designed it was rare an issuE could spread but firmware for nokias was released to plug security holes in browsers and sms I know that for fact. but droids did have a major issue with malware apps discovered in march and apple are at present as witnessed on the wifes Ipod touch which when not used was trying to access porn sites and alsorts. How would O2 or any phone company gurantee to protect your phone? Do they filter all your apps and montior what you download or load on via blue tooth or sd card? Do they stop u. "Sideloading" .apks? Do you check the permissons granted to software and does o2 double check? One thing I have learned about phone companies is customer support and account mangers will say anything to keep the customer Smiling. They will let the tech people try n deal with the issues :P

Another point is whatever you decide do the phone companies allow updates created by the makers to patch security issues and do they inform users? Rim on os 6 had an issue with its browser which was a javascript related issue a month or two ago. Many of the UK phone operators have not updated the firmware to patch the problem either by allowing the customer to load if they want or by pushing an update.
Droids don't always have access to the latest os's especially if you purchase and use the Phone companies approved firmware.

That's why many like apple as they control the firmware not the phone company. You can of course update your self a blackberry or droid but then you possibly lose support from your phone provider.
Possible exploits of weakness in the browser are the biggest risks on smartphones it appears..


By the Way I think the Droid Apple and Blackberry Phones are all decent Phones which realy you need to play with and use plus read up loads about to see which one suits you best.

The biggest issue is unless plugged into a charger in the home/office or Car some Phones can have Battery lifes of 6 to 8 hours!! Even less if you really use certain functions!!