This is true in general for digital nomads, whether they blog/podcast or even just freelance, a lot of whom continue to work a few months at a time in foreign locales on tourist visas. I've seen their blogs refer to visas as a gray area. I'm pretty sure this is a mistake.
I've looked at a few of the digital nomad guidence sites and none I've seen do much more than say its vague. If Steven King goes to the UK and writes a few news about his book, is he working? If I visit the Uk from the US on vacation and I answer a work email using my phone am I working? Probably these countries don't care, but where is the line between answering an email and "working" while living in the uk in a hotel room for a month?
I've never worked anywhere but the us, but as a dev I could work remotely anywhere in the world if I was certain it wasn't illegal.
I got permanent re-entry work permitted for Uruguay at very low marginal effort. It's not bali-cheap but it's developed, different, gateway to all of south America, and high tech friendly.
There are economies which would welcome you as a digital nomad.
entering the UK under a tourist visa or waiver program, you must be able to fund your stay. The tourist visas are No Work or Recourse to Public Funds. If you are funding your stay in the UK by working remotely, you are not abiding by the terms of your visa. This isn't the same as getting an emergency call out while on holiday.
How does the border agency know? They ask you a whole bunch of questions upon entering the country. So if the plan was to work remotely you'd end up lying to them. Digital Nomads calling it a grey area is often a nice way of saying "unless you tell someone the truth, you'll be fine"
If it's something you plan on doing, I'd highly recommend knowing the regulations for each country yourself and not relying on a third-party website to tell you things. That way you decide what you say to whom and what risk you take.
Define "living." As a US citizen, I've gone over to the EU, including the UK, for multiple weeks to attend multiple conferences, have customer meetings, etc. I've never been anything but 100% upfront in answering any questions about the purpose and duration of my visit honestly and have never had an immigration official so much as blink at my answers.
I know that some countries (such as China) do require business visas for attending a conference and I've to get letters of introduction, etc. in order to get my visa. But it's never been an issue in Europe.
