don't ever use the card, anonymous or not, in the country where you are a tax resident.
This should be ONE of the commandments of the OCT forum!
Seriously, this is TOO important NOT to be repeated!
But are anonymous prepaid debit card safe then?
I can tell you from personal experience:
Suppose you are buying things like groceries, meat, chicken, fruits, vegetables, and milk, paying at a pharmacy, paying for medical visits, paying your insurance, putting fuel in your car, paying for train rides, buying a plane ticket, buying books at the bookstore, borrowing books at the library, paying your University tuition, eating at restaurants once or twice per week, paying your optometrist, paying your gym membership etc etc. In that case, you have absolutely NOTHING to worry about. Nobody cares if you are trying to "survive".
Now, if you frequent nightclubs, and super expensive restaurants every day or more than once per day, purchase high-end luxury items like Louis Vuitton, Versace, Hermès, Prada, Patek Philippe, Rolex, car payment/rentals on supercars, pay escorts, pay on escort sites etc etc., you are royally f*cked...especially if the purchase is +€10K or "structured" to obfuscate that it is more than +€10K.
In certain countries, including but not limited to the USA, Canada, Australia, the Netherlands, Belgium, Spain etc., there are thousands of informants with monetary incentives/rewards to report the "suspects". This is easily confirmed with a rudimentary search using Google. These "informants" are NOT hanging out in University libraries or in grocery stores.
Govern yourself accordingly!