Earlier quoted context omitted.
Seems reasonable to me: ... This site and this directory were driving up server load averages, which causes instability for all users on this server. Our block on this site appears to have blocked over 150,000 connections in about half an hour. This is simply more than is appropriate for a shared server. You may want to review your domain's traffic logs to see what kind of traffic this site is getting. The logs for t…
Sure, it's reasonable, if your desired outcome is to lose a customer by a) demonstrating a lack of burst or headroom capacity and/or graceful degradation/priority scheduling capability, and b) being a dick about it. Alternatively one may intervene with a positive approach and framing viz. "we have temporarily [provisioned additional capacity / relocated your storage to another spindle / mirrored your content to a les…
Agreed. Also consider that shared hosting packages are very much providers scraping the bottom of the barrel for some marginal extra revenue. Shared hosting customers are not the highest priority of customers, unless your entire business is based around shared hosting (in which case, you are likely operating as amateur hour anyway)