There are many cruise ships that park at Istanbul and then run buses to the major tourist spots. They will have a guide and herd their folks through. So we could have been looking at something more or less ourselves and then some guide would pull up next to us and start talking to 25 people. Generally, they could be out-waited or avoided by some creative ducking and weaving. If the guide was speaking English, we sometimes got freebie information, but usually our guide book (Rick Steves' Istanbul, aka "Rick Steves' proxies' Istanbul" b/c he did not write it) told us what we needed to know. When one of us would have it the other would ask "What do Rick's proxies say about this?"