I really wonder what the implications of this would be, i'm sure they wouldn't think twice about doing it. Is there anything at all that can be done to prevent this?
Not much, apart from...
1. abandoning BTC in favor of a new currency specifically engineered to counteract this (Litecoin didn't do enough in this regard)
2. making BTC transaction fees a thing, and restoring profitability to small mining operations.
If you send BTC without a fee, you're killing BTC.