No, it's because of the name of the transit line -- the South Lake Union Trolley -- and, more importantly, its acronym.
[T]he story that the neighborhood's streetcar line now under construction was called the South Lake Union Trolley until the powers that be realized the unfortunate acronym -- SLUT -- seems here to stay.
Officially, it's now the South Lake Union Streetcar. But the trolley name already has caught on, and in the old Cascade neighborhood in South Lake Union, they're waiting for the SLUT.
Officials say the whole thing is just an urban legend, that the streetcar was never going to be named the SLUT. But it doesn't seem to matter. Seattle Mayor Greg Nickels says "people can call it whatever they want as long as they ride it."
It's enough to make MARTA look like a prude.