Dr Disrespect's Twitch channel is currently down, and it's reportedly because he livestreamed the inside of a public bathroom. Offending footage isn't hard to come across online, and it does seem to be in breach of Twitch's terms of service: especially the clause that forbids the creation or uploading of content that's "invasive of privacy or publicity rights".
One video shows the streamer walking into a public toilet and locking himself inside a cubicle. It's not the most offensive or controversial material on the internet, but other people are clearly visible in the footage–and that's where the problem presumably lays.
"Any use of the Twitch Services in violation of the foregoing violates these Terms of Service and may result in, among other things, termination or suspension of your rights to use the Twitch Services," the Twitch ToS reads.
E3 2019 takes place at the Los Angeles Convention Center.