a lot of places selling indoor growing stuff from lights to nutes list as a private auction so no one can see what it was you bid on. on another note, ebay is a lot safer than say ordering from a pot magazine like high times. high times mainly has "potheads" order from it so its easy to get blacklisted. cops know who advertises in pot magazines so they can keep an eye on those companies or whatever.. ebay on the other hand would be where any normal indoor gardener would get their stuff for growing strawberries, tomatoes, peppers etc. unless the seller or buyer mentions it will be used to grow pot, ya should be 100% safe.. lots of folks grow indoors now because of the economy/to save some cash. i think its more the affiliation you have than what you are actually ordering.
i know i would feel quite at ease about ordering a few lights and stuff on ebay.
on the other hand, you couldn't pay me to order supplies from a high times, cannabis culture or other pot magazine just for the fact if you are ordering from them, you are probably doing it to grow pot..