About the different causes of multiple origin ASN(MOAS) problem

Hi, I'm trying to find all causes of multiple origin AS problem(MOAS) as follows, but not sure if it's complete. Also please let me know how popular each item is, especially item 3 and 4 that I'm very curious about. 1. Internet Exchange Points, we have observed a list of this prefixes, although they generally are not announced to the DFZ. 2. Anycast, rare, but occurs sometimes, for example, 192.88.99.0/24, 2002::/16, and 2001::/32 3. Multi-homing with Private AS number 4. Multi-homing using static route (customer doesn't have AS number) 5. Misconfiguration 6. Hijacking 7. What else? Thanks, Yaoqing