Salesforce employees are pushing back against the company’s plan to create an NFT platform.

Salesforce announced in early February that it was working to develop its own NFT platform and NFT Cloud. Co-CEOs Marc Benioff and Bret Taylor told employees at an online event. NFTs have become increasingly popular, with some fetching millions of dollars.

It seems Salesforce employees are not impressed with the plans, with hundreds of them signing an open letter of protest, according to Thompson Reuters Foundation News. The employees took multiple issues with the company’s plans, including the environmental impact of NFTs and their being “unregulated, highly speculative financial assets.”

The environmental concerns are becoming a common refrain of critics of blockchain-based tech. Mozilla was forced to abandon plans to accept cryptocurrency donations over crypto’s environmental impact, and Wikipedia is under similar pressure.

It remains to be seen if Salesforce will abandon its plans, or merely alter them to address employee concerns.