"I thought most glazes today were safe now. :[ That's really disheartening."
Glazes used in the USA for cookware/dishes are regulated to be safe. But not every pot that gets glazed or painted in this country, even today, is planned for food use. World-wide, standards vary or in some cases, don't exist. And there are oodles of unsafe ceramics floating around, pre-safety standards, even in this country.
I know this because a relative of mine was into antiques, and bought and sold such things. Some popular, collectable dishes were ok to display, but too toxic to use for their original, intended purposes. Any antique ceramic can be a risk.
For example, your Aunt Minnie has an old figurine of a dragon that Uncle Joe brought back from Japan after WWII. She gives it to you because she knows you've always admired it. You think it would be great in your fish tank. You research it on the internet and find out that the glazes used on it were toxic. Aren't you glad you didn't put it in your tank? ;)
I only trust glazed ceramics that I know were manufactured for food purposes under current safety standards OR that I absolutely
know are covered in safe glazes.