Hmm… I see what you mean, but I kind of went in the other direction… snail mail means serious… if they had sent an email I would have possibly ignored it.
TBH, kudos to my ISP (Cablecom Switzerland) for reacting quickly.
My PC was infected on the 5th Dec at 22:30, they sent a mail on the 6th, which I got on the 7th.
That is very good for a big corporation.

In any case I had already killed the virus on the 5th (I hope), but if they do this to all PCs on their network they could really make a difference.

I also received a notification from them saying the activity has stopped now, so the case is closed on my ISP’s side.

Now I just want confirmation that all my home network PCs are clean.