This is inspired by a similar thread on the Michigan Radio & TV Buzzboard:
http://www.mibuzzboard.com/phpBB3/viewtopic.php?p=552477#p552477
There are isolated examples on other threads here, patricularly the "Worst Cable Systems" thread.
http://www.mibuzzboard.com/phpBB3/viewtopic.php?p=552477#p552477
This thread, as the title says, is specifically about any cable system, even MATV ones that only serve one particular building, that does not carry all of the network affiliates (specifically the Big Four, PBS, The CW and My Network) from the television DMA in which the system is situated in.
An MATV system at a senior complex in Temperance, which is located in the Detroit DMA (as is all of Monroe County) despite being right next to Toledo, only carries WXYZ, WJBK and WKBD from Detroit. The remaining networks are only available from Toledo and even WJBK is carried alongside WUPW.
There is also the WOW headend in Perry, which is in Shiawassee County, the entirety of which is part of the Flint-Saginaw-Bay City DMA though it is much closer to Lansing. However, the only stations from that DMA that are carried on this system are WSMH and WAQP, the rest of the networks are all from the Lansing DMA.
There are isolated examples on other threads here, patricularly the "Worst Cable Systems" thread.