Allison's Yahoo mail got hacked last weekend, and she spent all weekend with technicians to fix it. She's worried she lost all her contacts. Leo fears that the technicians that charged her $200 to fix it were actually hackers pretending to be Yahoo customer support. Leo thinks they probably made her situation worse by installing key loggers and other exploits that'll turn her computer into a botnet zombie.
Leo advises that Allison cancel her credit card, and try and get her credit card company to reverse the charge. Then she should backup her data, format her hard drive, and reinstall Windows from a known, good source.
She should also change the email password to all her webmail accounts and turn on second factor authentication. In fact, Leo recommends dumping Yahoo and going with Google's GMail instead.