WESTLAKE HILLS, Texas -- WESTLAKE HILLS, Texas (AP) — His voice thick with emotion, Vice President Joe Biden on Wednesday again toured the National Domestic Violence Hotline he helped create, calling victims of such abuse "prisoners in plain sight."

Housed in an unmarked building in suburban Austin, the hotline was founded in 2006, two years after Congress approved the federal Violence Against Women Act, which Biden sponsored while still a senator from Delaware.

"I came primary to say thank you," Biden told a packed room of staff members and media. "There's nothing I've been involved with my entire career that makes me prouder, that I think is more sustaining, is more consequential than the work you all do."

Biden previously visited the hotline as vice president in 2009 and as a senator three years earlier.

Hotline President Katie Ray-Jones said more than 100 staff members handle about 22,000 calls a month — but that capacity issues meant they still were unable to get to almost 52,000 calls in 2012 alone.

Meanwhile, the center has seen traffic on its website increase 30 percent during the last 12 months, and it is now receiving about a third of its contacts via Internet. Biden's visit coincides with the unveiling of a new chat service that allows communicating with the hotline via instant message and other Internet-based programs, thanks to a $250,000 donation from Verizon. The service will only be available Monday to Friday between 9 a.m. and 7 p.m. Central time, to start, but the hotline hopes to raise additional funding to eventually offer it around the clock.

Ray-Jones said the hotline previously set up a chat service pilot program and saw the number of victims reporting sexual violence spike. It's now bracing for that trend to continue after the rollout of the full chat service.

"The Internet and a chat function offers an additional layer of privacy that you don't have over the phone," she said. "There's another layer of vulnerability when I'm on a phone call and you can hear that I'm crying."

Ray-Jones also said that in some cases, women who are abused don't have access to phones or can't call because their abuser closely monitors phone records. Chatting via Internet can overcome some of those hurdles.

The hotline receives $3.2 million annually in federal funding. Biden said he and President Barack Obama would like to direct $4.5 million for it, but that because of across-the-board government spending cuts known as the sequester, it could fall to $2.9 million.

Biden also toured the facility, personally greeting all of the workers fielding calls. Staffers gave only their first names, citing the hotline's confidentiality rules — but one of the first people Biden greeted was Cassandra, who took the hotline's 3 millionth call July 20.

Meanwhile, an employee named Cindy was still on a call when she saw Biden and began dancing on the balls of her feet with excitement. Upon finishing the call, she rushed forward when Biden smiled.

"I knew you'd remember!" she cried, enveloping him in a bear hug. "I've been here since 3:30 this morning waiting for you."

Biden visited with actress Mariska Hargitay of "Law & Order: Special Victims Unit" fame, who he described as being such a passionate advocate for the cause that he didn't know how she had time for a day job. Hargitay also chatted with those fielding calls, and grew teary-eyed when she told them: "I'm so honored to be here."

"You can stay!" said one of the center employees, drawing chuckles.

According to the Texas Democratic Party, the most-recent state statistics show that in 2011 there were 177,983 incidents of domestic violence, and that 102 women were killed as the result. Some 11,833 Texas adults and 14,578 Texas children ended up in shelters because of domestic violence that year — but 21 percent of adults seeking shelter were denied due to lack of space.

Also on HuffPost:

Loading Slideshow...