When the the virtual tag is used with each to create a series of <my-tag> for each element of some data, then this.tags['my-tag'] grows when the data receives more elements but it doesn't decrease when elements are removed.
BTW, if I iterate the tags directly without the virtual tag, the this.tags['my-tag'] doesn't take tags of the same name into account that are placed outside of the loop. This seems to be what #1519 is about, though. Just mentioning it because this was the reason why I switched to using virtual in the first place.
(I'm having some issues with jsfiddle removing external resources. Make sure you check the console for the version of riot being used)
tried it on chromium 53.0.2785.143 (64-bit) and firefox 49.0.1, both don't work
This happens with 2.6.4 and 3.0.0-alpha.11