Ever since New York's attorney general specifically targeted newsgroups and usenet for child pornography (which is deplorable), there's been a backlash of ISPs dropping support for the network altogether. Crunchgear lists Time Warner, Verizon and Sprint either cutting off all support or limiting it to various non-binary categories, making people who access usenet for an easy way to download free movies pretty angry. Will ISPs dropping it mean the start of a slow death of usenet as a whole, or will third-party usenet access sites (which charge fees) keep it alive for a while yet? [Crunchgear]
I seriously doubt this will kill Usenet. ISPs usually have a limit to how much you can download from their Usenet servers each month, and have terrible retention. Any serious Usenet user uses (wow) a third party provider. It would be difficult, if not impossible, for ISPs to block those because many of them are able to serve on Port 80. They might as well try to shut down IRC while they're at it.