Verizon Wireless acknowledged today that its billing system is having issues for customers across much of the US. According to subscribers tweeting on the #VerizonOutage hashtag, issues have extended over the last two days, preventing them from doing simple things like activating a new phone or paying their bill. In tweets and a message on its news page, Verizon said the issue is affecting customers in the Northeast, Midwest and Southern regions, but has yet to offer an ETA for a fix.