Thanks. It turns out that an ad blocker I installed in Firefox was blocking all the social media buttons, including the pin buttons. There is a setting in the new ad blocker that allows you to disable social media buttons and it was on by default. My question had to do more with copyright than with being able to pin. Even with the ad blocker on, I can pin in the sense that my software allows it, but I usually don't unless there's a pin button on the page. Not many people know this, but when you pin, you are actually creating and publishing your own full-sized copy of the image on the Pinterest website, not making a pointer to the image on the copyright holder's site. Unless the copyright holder has given you permission to pin, that's a violation of copyright law. Some creative types, especially photographers, are not OK with having their images pinned. Several years ago when Pinterest was new, I asked Vicki if the designers were OK with having their images pinned and she said she'd ask them. The pin buttons appeared shortly afterwards, so I pinned shop images freely. When the buttons disappeared, I thought maybe the designers had changed their minds.