A dialer is a very small program, often installed using the ActiveX technology. Dialers often promise access to free porn, free games or free cracks for commercial software. Once installed, a dialer offers to use your dial-up device to call in to the service, usually calling a quite expensive toll number. Some dialers explain the costs of the connection they will be making, like it is required by local law in some countries, but many dialers just display a button offering to connect, without informing the user of what is happening behind it. In the worst case, the dialer sets up the expensive number as the default Internet connection, meaning the user will have to pay high rates for being online, without even knowing it until receiving the next bill.