side_tag_cloud block, right?

Yes

Automated response: side_tag_cloud block doesn't check permissions to content behind tags (keywords)

Content may be inaccessible or non-validated, and the block should be able to check this.

That said, there is a major performance hit doing so.
The check is implemented via a new block option.
Sites may want to enable the check for small sites if they are concerned about keywords leaking. However, for larger sites leaking likely would not be an issue given prevalence of existing accessible keywords.