I couldn't help a mischievous thought when I read about the suggestion from what I might call a "traditionalist tendency" (no offence or personal slight intended, but I think the phrase does reflect accurately a certain reality in the Church) that a new Syllabus condemning infallibly the abuses and misinterpretations of the Second Vatican Council should be prepared by the Supreme Magisterium of the Church. The suggestion is reported here and here.
The thought is not sinful - after all, it wasn't initially willed but inadvertent. Neither do I think its further propagation to be sinful - though clearly the thought has now been "entertained" rather than dismissed, or at least attempted to be dismissed, from the mind.
And that thought was to advise that those of a traditionalist frame of mind might exercise some caution with this suggestion. After all, should the Syllabus be produced in the manner suggested, and something appear in the list of condemned propositions that they think should not be there, they might find themselves in a bit of a pickle.