After the shell has healed, caretakers sand down the leftover adhesive and remove the wire and bra clasps -- a step the turtles probably refer to as "second base." The almost-good-as-new turtles are then returned to the wild, blissfully ignorant of the massive debt they owe to some old underwear. (Has this been Victoria's secret all along?)
The idea was popularized when a wildlife rehabilitation sanctuary in rural Iowa asked the internet for old bra clasps to mend some broken turtles, and the post went viral. In fact, they were soon drowning in bras (even more than wildlife rehab workers normally are, we mean), and had to ask people to stop sending them. Other animal rescue centers around America and the world began doing the same thing, with equally overwhelming results. If there's one thing people like more than helping animals, that's helping animals while getting rid of their junk.