I don't use my FB account anymore and it was disabled 3 weeks ago, it was strange since generally no use = no abuse.
Then my friend's account was also disabled, we both released the inner workings of WA protocol along with API PoC a while ago (https://github.com/venomous0x/WhatsAPI) and it got popular, so we suspected that as the only relevant common thing.
Today, Tarek (https://twitter.com/tgalal/status/583508825329819648) who also built unofficial sort of WA clients, confirmed it's the WhatsApp thing.
This makes me think of the rationale of:
1) Disabling someone's account for allegedly violating another service's terms.
2) Three years ago.
3) At time where WhatsApp was an independent company.
4) And whether this practise will expand to Instagram? Parse? future acquisitions?