About 3 weeks ago my 2 years Pro-Account was deleted less than 2 months after I purchased it, as a renew of previous Pro Account. I didn’t receive any warning before the deletion, nor any explanation after.
Thus I sent a mail to Flickr-support and asked about it. Was answered that “someone sent an Abuse Report”, Flickr “deterrmined that my content and/or behavior was in violation” with the following rules:
“”Do upload content that you have created. Respect the copyright of others. This means don’t stealphotos or videos that other people have shared and pass themoff as your own.”

“Don’t upload anything that isn’t yours. This includes other people’s photographs and/or stuff thatyou’ve collected from around the internet. Accounts that consist primarily of such collections may be terminated.”

Now, as I never posted anything which wasn’t created by myself, 10 days ago I asked Flickr which of my posts was reported, as I could easily prove it was made by myself (my contents are mainly hand-made drawings and a few fotoshopped pictures).
Still waiting for an answer.