US man gets 15,000 birthday texts after sons' hilarious billboard prank

Chris Ferry's birthday wishlist probably didn't include 15,000 texts from strangers.

The New Jersey native will turn 62 on Saturday, and his sons Chris and Michael had no idea what to get him. Chris Jr recently bought a billboard outside Atlantic City to advertise his addiction recovery centre, and thought his dad could do with one too.

He called his brother and suggested they put a giant photo of Ferry on a billboard in his area, along with his phone number encouraging people to call or text hum.

"We thought people in the local area and his buddies would call in, and this would be a fun memory," he told CNN. "We did not know that it was going to be like this."

The billboard, which is also outside Atlantic City, features a huge photo of Ferry's face next to the words 'Wish my dad happy birthday. Love, your sons.'

Ferry first realised his sons had pranked him when he received a happy birthday text from someone called Nick.

"[I was] saying 'Nick? Nick who? You don't know me, how do you know it's my birthday?'" Ferry told CBS. "[They] saw it on a billboard."

At first he thought the idea was hilarious, and immediately drove to the billboard to have his picture taken with it.

But as more and more birthday messages from unknown numbers began to roll in, including from places as far away as Germany and Africa, his amusement turned to frustration - and then anger.

"It was fun until this morning," he told CBS. "Then I wanted to kill them. But I'm going with it, having a good time."

He received so many texts and calls that he was no longer able to use his phone, and has since had to change his phone number, ending his son's prank - although the billboard will stay up for another three weeks.