RBS Bank Accounts

Me and the missus have a joint savings account at the RBS soley in our names. One of our sons (23 years old) has his own seperate current account also with RBS soley in his name...(Same branch). He lives with us so the two accounts show the same address The bank are chasing him as hes overdrawn ect and they have now 'suspended' his account until he's paid them what he owes them I hear some horror story about the banks raiding other accounts to pay off an overdrawn account . I'd always assumed this was other accounts in the same name as the person whos was in debt to them. Couild someone reassure me that they have no call on the funds in our account as its the same surname and the same address ? Thanks