Everyone here will be aware, no doubt, of the incredible popularity of Ukraine Post's 'Warship' stamp; part of the country's self-promotion in its fight against the Russian invasion.
Private dealers were cashing in on the former (which sold out over a million copies, I believe) by reproducing its image on Ukraine Post's 'personalized stamps' product, leading people to believe that they were 'official' stamps. Ukrposhta has since banned use of the warship image on 'personalized stamps'.
Here's an example, with the offending stamp (top left of the row) on a commemorative cover issued by Cossack Post, a private producer based in Lviv who regularly releases Ukrainian nationalist stamps using the 'personalized stamps' product, including controversial designs that are not featured on his website.
The asking price of the above cover is US $170.00 on eBay
Here's a 'personalized stamp' before being personalised. There have been a number of designs over the years. A perforated tab contains the country name and value, giving it postal validity, but can be removed if desired.
Stamps of various nations are forming an interesting backdrop to the war in Ukraine.