Some dishonest players in RuneScape are tricking other players in the game by changing quantities at the very last minute causing the other player to receive much less than they expected.
So for example they offer 4 million coins, and then at the last second just as you are pressing accept they change it to 400K coins, and hope you won't notice.
Therefore you need to read the trade confirmation screen very carefully!. Double check that you getting the number you expect. Some players are failing to notice the number has lost a zero off the end, and are getting scammed.
Make sure that you read the trade confirmation thoroughly before clicking the accept button, never be persuaded to click through the windows quickly.
To help you out, we have just made some changes to the confirm screen to make the amounts more obvious. Amounts are now coloured coded, seperated with commas, and written in both words and numbers! This will hopefully make the above scam much less effective, but you should still be careful.