Actually, there is no evidence that Tor is any shadier than the rest of the Internet, especially given that most attacks and vandalism originate from botnets and other compromised systems, not Tor.
Great resource, a surprisingly clear and detailed introduction to the various attacks faced by websites!
The relevant part:
> "we concluded that approximately 1 in 380 http requests coming out of Tor is verified to be malicious, while only 1 in 11,500 http requests coming out of a non-Tor ip were verified to be malicious. In essence, an http request from a Tor ip is 30 times more likely to be a malicious attack than one that comes from a non-Tor ip."
Akamai published an analysis that affirms this:
https://web.archive.org/web/20170317110115/https://www.akama...