Which is safer to lock your bike to, rack with other bikes or away alone?
When you need to park your bike on the street temporarily (no more than few hours), if there is a bike rack area where several other bikes have been locked, is it better to lock your bike among others, or instead lock your bike alone to a signpost nearby, away from those bikes?
My concern about locking bike with other bikes is that there may be a potential thief who either is an owner of one of the bikes (cyclists would be more interested in your bike/bike parts ) or is paying close attention to the apparent bike parking area, and if he tries to steal your bike (or bike parts/accessories) it's not obvious to passersby. On the other hand, if your bike is alone some steps away, it may be a clearer target.
Depends more on the bike you have than anything else. A cheapo POS can be locked anywhere and have an equal chance of getting taken. Make a NICE bike stand out, like by locking it up separately, and you could well be hanging a sign on it.
A thief who owns a bike, and uses it as BAIT at a bike rack? Most thieves aren't capable of that depth of thought.
Lock yours up with the others, and use a better locking system than anyone else; make yours a harder target to get.