Actually, they are Berthing[1][2] the Dragon craft with the ISS, which means something slightly different - grabbed by the thing you are connecting to and pulled in, vs. a (controlled) bumping into the thing. I believe that Nautical terminology is where that comes from, and means the same there e.g. berthing ships with ropes and dock hands.

1. https://en.wikipedia.org/wiki/Docking_and_berthing_of_spacec...

2. http://space.stackexchange.com/questions/13665/what-is-the-d...