viewers at once. Live cam sites are very popular. Big sites like Chaturbate or LiveJasmin are among the 100 most popular websites according to Alexa Internet. Other formats Other formats include text and audio files. While pornographic and erotic stories, distributed as text files, web pages, and via message boards and newsgroups, have been semi-popular, audio porn, via formats like MP3 and FLV, have increased in popularity. Audio porn can include recordings of people having sex or merely reading erotic stories. (Pornographic magazines are available in Zinio format, which provides a reader program to enable access.) Combination formats, such as webteases that consist of images and text have also emerged. Legal status The Internet is an international network and there are currently no international laws regulating pornography; each country deals with internet pornography differently. Generally, in the United States, if the act depicted in the pornographic content is legal in the jurisdiction that it is being distributed from then the distributor of such content would not be in violation of the law regardless of whether it is accessible in countries where it is illegal. This does not apply to those who access the pornography, however, as they could still be prosecuted under local laws in their country. Due to enforcement problems in anti-pornography laws over the internet, countries that prohibit or heavily restrict access to pornography have taken other approaches to limit access by their citizens, such as employing content filters. Many activists and politicians have expressed concern over the easy availability of internet pornography, especially to minors. This has led to a variety of attempts to restrict children's access to internet pornography such as the 1996 Communications Decency Act in the United States. Some companies use an Adult Verification System (AVS) to deny access to pornography by minors. However, most Adult Verification Systems charge fees that are substantially higher than the actual costs of any verification they do (for example, in excess of $10/month) and are really part of a revenue collection scheme where sites encourage users to sign up for an AVS system, and get a percentage of the proceeds in return. In response to concerns with regard to children accessing age-inappropriate content, the adult industry, through the Association of Sites Advocating Child Protection (ASACP), began a self-labeling initiative called the Restricted to Adults label (RTA). This label is recognized by many web filtering products and is entirely