Nasty hackers have been stealing PayPal accounts and credit card information in order to make fraudulent purchases of Diamonds (Runes of Magic's item shop currency) and gift them away to their main accounts. This situation has prompted Frogster Interactive, the folks behind Runes of Magic, to make a change to the Diamond trading policy.
Customers who purchase Diamonds through PayPal, Credit card, or through PlaySpan will not be able to trade or gift their Diamonds away to other accounts. Instead, the Diamonds will only be made available to the account for which they were purchased.
The original announcement can be viewed here.