Not so common in North America anymore, but very common in S. America and Europe. Brazil expect every drink you have to be spiked with scopolamine especially if you're a rich looking tourist and a girl who makes $50/week wants to clear out your hotel. I would expect the same in the Czech Republic too, but since bartenders are in cahoots with the thieves there you'd need to bring your own straws.

I also don't think this guy's idea will work very well, and instead will create a false sense of security instead of just watching your drink, which is probably the reason cases of Rohypnol/GHB have declined in N. America since there's so much education about guarding your drink or tossing it if you leave it alone. Bouncers also provide benefit denial of this crime/scam, and will usually stop somebody walking out dragging a girl until they find her friends, at least here they do.

Another problem is I see criminals just bringing in their own straws and switching them while dumping in the drug. Bars are unlikely to order these glasses unless they are inexpensive, they go through so many broken glasses it's not worth it to them to swtich. Their bleach + high heat cleaning methods might render the protection useless too after a few washings.