WLTX says eight of those nine Verizon Wireless employees work at the call center in Elgin (near Columbia). The ninth person arrested works in the Charleston area. That employee (according to their Facebook page) works in the Finance department.
The Department of Revenue told WISV that the suspects filed W-4 forms with Verizon Wireless claiming to be exempt from paying taxes and also failed to file tax returns for several years.
Both stations reported that more arrests could be coming and more details about the alleged crimes would be released.
***Update 1/14/13*** - I spoke with a North Charleston VZW Call Center employee who said they heard more arrests have been made, including at their location. No official word from authorities has been released about this allegation.