High-tech "Sabbath elevators" may not really be kosher:

...The rabbis wrote that this new technology, which was explained to them by elevator technicians and engineers in "a written and oral technical opinion," made them aware for the first time that using Shabbos elevators may be a "desecration of the Sabbath."

They did not name the offending technology. But for several years there has been debate among Orthodox rabbis in Israel over whether devices that measure the weight in an elevator car, and adjust power accordingly, effectively make entering a car the equivalent of pressing a button.