Here is a link to the DreamHost TOS...
and a quote from the relevant section...
[color=#0000CC]"Servers are shared with other customers, and as such IRC-related activities or severely CPU intensive CGI scripts (e.g. chat scripts, proxy scripts, scripts which have bugs causing them to not close properly after being run) are not encouraged. BitTorrent clients, IRC bots and bouncers (BNC) specifically may not be run on any DreamHost Web Hosting server."[/color]
While the TOS doesn't specifically mention BitTorrent Trackers, I believe they could be seen as 'severely CPU intensive'
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