Tens or even hundreds of thousands of computer users could be unable to get online this summer.
The FBI is warning all computer owners to check for a type of malware, called "DNS changer," which is similar to a virus.
PCs infected with DNS changer were used by a group of hackers for fraud. Federal agents say they've caught those responsible, but a temporary solution keeping the infected machines on-line will go away in July, and users won't be able to connect to the internet. You can whether your computer has been infected by following this link.