[tjkrusinski]

No, older smart phone cameras lacked IR filters because the IR filter didn't only block IR light, but also a distribution of wavelengths around IR. Filtering out IR means many of the visible light wavelengths are attenuated as well, decreasing the amount of light arriving at the sensor.

With better noise reduction algorithms, more sensitive sensors and lower noise sensors, IR filters are now almost always used in smart phone cameras.

[jandrese]

Also, without an IR filter those cameras could partially see through light clothing in bright conditions. This of course formed a creepy online community and enough backlash that the manufacturers decided to include IR filters for all future products.