The best (worst) example I've seen so far is this ad (since expired) that was for a place at 2nd and Upshur that said it's in Columbia Heights. Not even close, guys.
Another, more reasonable one is this one that says Petworth/Columbia Heights for a place at Georgia and Upshur, which is still pretty far even if you stretch the neighborhood's boundaries. Other ads, like this one, tout their short drive to Columbia Heights and Adams Morgan, while still others say Petworth (N. of Columbia Heights).
We've hit the big time, folks! Seen any other ridiculous ones?