A lot of telecoms avoid it like the plague because: 1. it destroys network observability 2. they have so much IP space they don't even know what to do with it.

A lot of telecoms avoid it like the plague because: 1. it destroys network observability 2. they have so much IP space they don't even know what to do with it. /30 everything! Management networks are a different story, but hey, some Tier 1's think they're so large they don't even need OOB anymore! (haha...)