Pole sana my friend, The guy seems to be that simple user who can quickly clicks remember my password pop ups msg from modern browsers.So the thief has decided to login and change all the emails.Possibly to follow an additional benefit within emails in your inbox.Or just to punish him even more.Or just to get any information from other guys about the tracking of the laptop. I have been recieving these kind of complains from simple clients who dont care to allow the browsers to remember their passwords.Some of them has paid a good prices.Some have diverted some payments to their account.And to make things worse they have created two way communications that legalize the transactions.Some have even gone further to charge the looser some amount of money as processing fees for the expected money(though the money have been routed other account).This has been occured to guys expecting money from from abroad in scenarios where people dont use phone confirmation much. I think the only way is to use proper ways from service providers to reset things.

Even if the laptop was stolen, how would someone change the passwords? Don't they require you to login first before you can change any password?

Anyway, I guess it the thief went this far they may have changed the recovery secret questions as well.

With Yahoo!, you could get in touch with customer support and they can assist recover the account. With Gmail, I am not sure.