There have been speculation and rumours that bank accounts in Thailand will be taxed.
If you had heard this, then, what you hear is complete rubbish. As with any country in the world, interest is taxable. Only people that have 20.000 Baht a year will be taxed. People on a lower income will not be affected.
Just be warned tho, for those of you that have multiple accounts with different banks, will be taxed on their combined interest is it exceeds that figure