I would like to know if you have the same issue on Google.
Basically all my meta descriptions are duplicated by spam sites. When I report them my ranking is going back up, and I am not sure if the search engines go after the spammers using legitimate meta descriptions. I also discovered that many meta descriptions duplicated could be found if you search and quote part of your meta descriptions.
How do you deal with that?
Those who can make you believe absurdities can make you commit atrocities.