As a server owner and in my concern for other server owners, donations is what pays for our servers hosts, upgrades, webhosts, etc.
There are people who donate the previous 2-3 months, and then just file a credit card chargeback via paypal afterwards. Making a donation is a choice from the player to support the server. Receiving a chargeback after donating to try to scam credits? items? this is considered "donation frauding". Some people do it to buy items and just chargeback to get their money back. Some people try to shut down servers by donating and charging back causing massive disputes. Regardless of what it is, these people are harmful to the RO community and in my defense to server owners, I suggest a sticky topic with all individual IP addresses / paypal emails of users who have committed donation fraud on your server. All owners who participate in this "blacklist" hopefully we can establish unified list to better server the RO community and stay away from certain individuals.