The pharmacy logo is more or less the logo of Lloyds Pharmacy in the UK. Close enough that it could be deemed to be infringing their TM IMO (it's tricky though with generic imagery).
If you're referring to this device [1], it's a matter of opinion. Personally I wouldn't really agree: the mortar and pestle is a common enough device and the leaf is a nice distinctive element.
The real risk in a situation like this is not really that you get a C&D from using it on your startup's landing page. The risk is that if you eventually tried to file a trademark for it, you would lose: either because some large firm's lawyers would oppose and have no trouble outspending you; or because, if you tried to file a trademark on an open-source logo you found on HN, you probably got bad legal advice.
If I had a natural-supplement startup, for example, I'd be fine using this open-source logo as a placeholder and developing a new logo once I wanted to start a trademark registration process.
IP law firms use automated software to scrape the trademark registration filings at the USPTO and other national trademark offices (ex. [1]). These software services automatically assess filings for possible infrigement. This is the most likely way for a bigco's lawyers to find out about your logo or company name - far more likely than them finding out about your startup from techcrunch or some other source.
Unfortunately for me, this happened to me. I was able to negotiate a coexistence agreement for my logo, but I could have done without the pain. If I were to start over from scratch, I would seriously consider doing the Apple/Google offline foreign filing trick [2].
The real risk in a situation like this is not really that you get a C&D from using it on your startup's landing page. The risk is that if you eventually tried to file a trademark for it, you would lose: either because some large firm's lawyers would oppose and have no trouble outspending you; or because, if you tried to file a trademark on an open-source logo you found on HN, you probably got bad legal advice.
If I had a natural-supplement startup, for example, I'd be fine using this open-source logo as a placeholder and developing a new logo once I wanted to start a trademark registration process.
http://enjoykingsheath.com/wp-content/uploads/2012/02/lloyds...