Vacation sure. But if you want to work from these countries then you can't be on a tourist visa.
If I go on a vacation and respond to a few work-related emails, am I breaking any laws because I'm working on a tourist visa? Yes, that is ad absurdum, but I'm trying to point out that it's not as clear cut. There is a line that international treaties define, and staying someplace (sometimes even up to 6 months) and working there doesn't necessarily have any income tax implications for you or your employer.
Law isn't code. Reasonable people (judges, normally) are able to decide what is "actually working" and "incidentally working while on vacation".