Not really from Tatoeba.
Some contributors put their sentences on Github under CC0 in their own space (account) before using them on Sentence Collector or other projects. Some of them are/were not aware about licence. And when putting a sentence on Github under a free licence (CC0), not all users are aware to keep the same licence when they reuse them (their own) on other projects when these projects manage other licence types other than CC0.
It would be interesting to me to contribute to Tatoeba (as CC0) and have it imported to Common Voice rather than adding directly to Sentence collector since my work then could be used for other things.