I believe in the fine print of their terms of service they give themselves the right to hold funds they believe are related to criminal acts until the account holder proves otherwise. But, yes, otherwise it would be something like conversion.
To quote Jay-Z "Uhh, yeah, guilty until proven innocent huh?"
People don’t read the fine print and will agree to anything...
The ladies should really look close at the fees that Venmo and CashApp charge.