No one can copyright a concept, which is why so many American TV shows can legally be nothing but mock-ups of already successful foreign programs. But a Canadian television network appears to think that CBS crossed the line this fall when it released Cold Case, a new cop show which bears several striking resemblances to a 6-year-old CTV program called Cold Squad. Both shows center around similar-looking female detectives who fight criminals and their own sexist co-workers in roughly equal measures as they attempt to uncover new leads in stalled cases. Oh, and the writer who came up with Cold Case did so right after attending a writing seminar in Canada.